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Difference between revisions of "intel/microarchitectures/gen9"
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−
{{intel title|Gen9 LP|arch}}
+
{{intel title|Gen9|arch}}
 
{{microarchitecture
 
{{microarchitecture
 
| atype            = GPU
 
| atype            = GPU
−
| name            = Gen9 LP
+
| name            = Gen9
 
| designer        = Intel
 
| designer        = Intel
 
| manufacturer    = Intel
 
| manufacturer    = Intel
Line 10: Line 10:
  
 
| succession      = Yes
 
| succession      = Yes
−
| predecessor      = Gen8 LP
+
| predecessor      = Gen8
−
| predecessor link = intel/microarchitectures/gen8_lp
+
| predecessor link = intel/microarchitectures/gen8
−
| successor        = Gen9.5 LP
+
| successor        = Gen9.5
−
| successor link  = intel/microarchitectures/gen9.5_lp
+
| successor link  = intel/microarchitectures/gen9.5
 
}}
 
}}
−
'''Gen9 LP''' (''Generation 9 Low Power'') is the [[microarchitecture]] for [[Intel]]'s [[graphics processing unit]] utilized by {{\\|Skylake}}-based microprocessors. Gen9 LP is the successor to {{\\|Gen8 LP}} used by {{\\|Broadwell}}. The Gen9 microarchitecture is designed separately by Intel and then integrated onto the same Skylake SoC die.
+
'''Gen9''' (''Generation 9'') is the [[microarchitecture]] for [[Intel]]'s [[graphics processing unit]] utilized by {{\\|Skylake}}-based microprocessors. Gen9 is the successor to {{\\|Gen8}} used by {{\\|Broadwell}}. The Gen9 microarchitecture is designed separately by Intel and then integrated onto the same Skylake SoC die.
  
 
== Codenames ==
 
== Codenames ==
 +
[[File:iris graphics logo.svg|right|200px]][[File:iris pro graphics logo.svg|right|200px]]
 
Various models support different Graphics Tiers (GT) which provides different levels of performance. Some models also support an additional [[eDRAM]] side cache.
 
Various models support different Graphics Tiers (GT) which provides different levels of performance. Some models also support an additional [[eDRAM]] side cache.
 
{| class="wikitable"
 
{| class="wikitable"
Line 37: Line 38:
 
{| class="wikitable tc2 tc3"
 
{| class="wikitable tc2 tc3"
 
|-
 
|-
−
! colspan="5" | Gen9 LP [[IGP]] Models !! colspan="9" | Standards
+
! colspan="5" | Gen9 [[IGP]] Models !! colspan="10" | Standards
 
|-
 
|-
−
! rowspan="2" | Name !! rowspan="2" | Execution Units !! rowspan="2" | Tier !!  rowspan="2" | Series !! rowspan="2" | eDRAM !! colspan="2" | [[Vulkan]] !! colspan="3" | [[Direct3D]] !! colspan="2" | [[OpenGL]] !! colspan="2" | [[OpenCL]]
+
! rowspan="2" | Name !! rowspan="2" | Execution Units !! rowspan="2" | Tier !!  rowspan="2" | Series !! rowspan="2" | eDRAM !! colspan="2" | [[Vulkan]] !! colspan="3" | [[Direct3D]] !! colspan="2" | [[OpenGL]] !! colspan="2" | [[OpenCL]] !! colspan="1" | [[Metal]]
 
|-
 
|-
−
| Windows || Linux || Windows || Linux || [[High Level Shading Language|HLSL]] || Windows || Linux || Windows || Linux
+
| Windows || Linux || Windows || Linux || [[High Level Shading Language|HLSL]] || Windows || Linux || Windows || Linux || macOS
 
|-
 
|-
−
| {{intel|HD Graphics (Skylake)}} || 12 || GT1 || {{intel|Skylake Y|Y|l=core}} || - || rowspan="9" colspan="2" style="text-align: center;" | '''1.0''' || rowspan="9" style="text-align: center;" | '''12''' || rowspan="9" style="text-align: center;" | '''N/A''' || rowspan="9" style="text-align: center;" | '''5.1''' || rowspan="9" style="text-align: center;" | '''4.4''' || rowspan="9" style="text-align: center;" | '''4.5''' || rowspan="9" style="text-align: center;" colspan="2" | '''2.0'''
+
| {{intel|HD Graphics (Skylake)}} || 12 || GT1 || {{intel|Skylake Y|Y|l=core}} || - || rowspan="11" colspan="2" style="text-align: center;" | '''1.0''' || rowspan="11" style="text-align: center;" | '''12''' || rowspan="11" style="text-align: center;" | '''N/A''' || rowspan="11" style="text-align: center;" | '''5.1''' || rowspan="11" style="text-align: center;" | '''4.5''' || rowspan="11" style="text-align: center;" | '''4.5''' || rowspan="11" style="text-align: center;" colspan="2" | '''2.0''' || rowspan="8" style="text-align: center;" colspan="1" | '''2.1'''
 
|-
 
|-
 
| {{intel|HD Graphics 510}} || 12 || GT1 || {{intel|Skylake U|U|l=core}}, {{intel|Skylake S|S|l=core}} || -
 
| {{intel|HD Graphics 510}} || 12 || GT1 || {{intel|Skylake U|U|l=core}}, {{intel|Skylake S|S|l=core}} || -
Line 58: Line 59:
 
|-
 
|-
 
| {{intel|Iris Graphics 550}} || 48 || GT3e || {{intel|Skylake U|U|l=core}} || 64 MiB
 
| {{intel|Iris Graphics 550}} || 48 || GT3e || {{intel|Skylake U|U|l=core}} || 64 MiB
 +
|-
 +
| {{intel|Iris Pro Graphics P555}} || 48 || GT3e || {{intel|Skylake H|H|l=core}} || 128 MiB
 
|-
 
|-
 
| {{intel|Iris Pro Graphics 580}} || 72 || GT4e || {{intel|Skylake H|H|l=core}} || 128 MiB
 
| {{intel|Iris Pro Graphics 580}} || 72 || GT4e || {{intel|Skylake H|H|l=core}} || 128 MiB
 +
|-
 +
| {{intel|Iris Pro Graphics P580}} || 72 || GT4e || {{intel|Skylake H|H|l=core}} || 128 MiB
 
|}
 
|}
  
Line 89: Line 94:
 
| {{intel|HD Graphics 535}} || SKL U - ULT 2+3 || K1 || L1 || 0x1923 || 0xA
 
| {{intel|HD Graphics 535}} || SKL U - ULT 2+3 || K1 || L1 || 0x1923 || 0xA
 
|-
 
|-
−
| {{intel|Iris Graphics P555}} || SKL Media Server 4+3FE || N0 || J0 || 0x192D || 0x9
+
| {{intel|Iris Pro Graphics P555}} || SKL Media Server 4+3FE || N0 || J0 || 0x192D || 0x9
 
|-
 
|-
−
| {{intel|Iris Pro Graphics P580}} || SKL H Halo 4+4E || rowspan="2" | 72 || N0 || J0 || 0x193B || 0x9
+
| {{intel|Iris Pro Graphics 580}} || SKL H Halo 4+4E || rowspan="2" | 72 || N0 || J0 || 0x193B || 0x9
 
|-
 
|-
−
| {{intel|Iris Pro Graphics P580}} || SKL WKS 4+4E || N0 || J0 || 0x193D || 0x9
+
| {{intel|Iris Pro Graphics P580}} || SKL WKS 4+4E || N0 || J0 || 0x193D || 0x9
 
|}
 
|}
  
 
<references group=devID />
 
<references group=devID />
 +
 +
== Performance ==
 +
<div style="overflow-x: auto;">
 +
{| class="wikitable" style="text-align: center; white-space: nowrap;"
 +
! rowspan="2" | Frequency !! colspan="15" | Peak Performance
 +
|-
 +
! rowspan="16" | &nbsp; || colspan="4" | Half Precision || rowspan="16" | &nbsp; || colspan="4" | Single Precision || rowspan="16" | &nbsp; || colspan="4" | Double Precision
 +
|-
 +
| Models || {{intel|HD Graphics 510|510}} || {{intel|HD Graphics 515|515}}, {{intel|HD Graphics 520|520}}, {{intel|HD Graphics 530|530}}, {{intel|HD Graphics P530|P530}} || {{intel|Iris Graphics 540|540}}, {{intel|Iris Graphics 550|550}}, {{intel|Iris Pro Graphics P555|P555}} || {{intel|Iris Pro Graphics 580|580}}, {{intel|Iris Pro Graphics P580|P580}} || {{intel|HD Graphics 510|510}} || {{intel|HD Graphics 515|515}}, {{intel|HD Graphics 520|520}}, {{intel|HD Graphics 530|530}}, {{intel|HD Graphics P530|P530}} || {{intel|Iris Graphics 540|540}}, {{intel|Iris Graphics 550|550}}, {{intel|Iris Pro Graphics P555|P555}} || {{intel|Iris Pro Graphics 580|580}}, {{intel|Iris Pro Graphics P580|P580}} || {{intel|HD Graphics 510|510}} || {{intel|HD Graphics 515|515}}, {{intel|HD Graphics 520|520}}, {{intel|HD Graphics 530|530}}, {{intel|HD Graphics P530|P530}} || {{intel|Iris Graphics 540|540}}, {{intel|Iris Graphics 550|550}}, {{intel|Iris Pro Graphics P555|P555}} || {{intel|Iris Pro Graphics 580|580}}, {{intel|Iris Pro Graphics P580|P580}}
 +
|-
 +
| Tiers || GT1 || GT2 || GT3e || GT4e || GT1 || GT2 || GT3e || GT4e ||  GT1 || GT2 || GT3e || GT4e
 +
|-
 +
| Ref (FLOP/clk) || 384/cycle || 768/cycle || 1536/cycle || 2304/cycle || 192/cycle || 384/cycle || 768/cycle || 1152/cycle || 48/cycle || 96/cycle || 192/cycle || 288/cycle
 +
|-
 +
| Base (300 MHz) || {{#expr: 384*.3}} [[GFLOPS]] || {{#expr: 768*.3}} GFLOPS || {{#expr: 1536*.3}} GFLOPS || {{#expr: 2304*.3}} GFLOPS || {{#expr: 192*.3}} GFLOPS || {{#expr: 384*.3}} GFLOPS || {{#expr: 768*.3}} GFLOPS || {{#expr: 1152*.3}} GFLOPS || {{#expr: 48*.3}} GFLOPS || {{#expr: 96*.3}} GFLOPS || {{#expr: 129*.3}} GFLOPS || {{#expr: 288*.3}} GFLOPS
 +
|-
 +
| Base (350 MHz) || {{#expr: 384*.35}} GFLOPS || {{#expr: 768*.35}} GFLOPS || {{#expr: 1536*.35}} GFLOPS || {{#expr: 2304*.35}} GFLOPS || {{#expr: 192*.35}} GFLOPS || {{#expr: 384*.35}} GFLOPS || {{#expr: 768*.35}} GFLOPS || {{#expr: 1152*.35}} GFLOPS || {{#expr: 48*.35}} GFLOPS || {{#expr: 96*.35}} GFLOPS || {{#expr: 129*.35}} GFLOPS || {{#expr: 288*.35}} GFLOPS
 +
|-
 +
| Base (400 MHz) || {{#expr: 384*.4}} GFLOPS || {{#expr: 768*.4}} GFLOPS || {{#expr: 1536*.4}} GFLOPS || {{#expr: 2304*.4}} GFLOPS || {{#expr: 192*.4}} GFLOPS || {{#expr: 384*.4}} GFLOPS || {{#expr: 768*.4}} GFLOPS || {{#expr: 1152*.4}} GFLOPS || {{#expr: 48*.4}} GFLOPS || {{#expr: 96*.4}} GFLOPS || {{#expr: 129*.4}} GFLOPS || {{#expr: 288*.4}} GFLOPS
 +
|-
 +
| Base (650 MHz) || {{#expr: 384*.65}} GFLOPS || {{#expr: 768*.65}} GFLOPS || {{#expr: 1536*.65}} GFLOPS || {{#expr: 2304*.65}} GFLOPS || {{#expr: 192*.65}} GFLOPS || {{#expr: 384*.65}} GFLOPS || {{#expr: 768*.65}} GFLOPS || {{#expr: 1152*.65}} GFLOPS || {{#expr: 48*.65}} GFLOPS || {{#expr: 96*.65}} GFLOPS || {{#expr: 129*.65}} GFLOPS || {{#expr: 288*.65}} GFLOPS
 +
|-
 +
| Boost (800 MHz) || {{#expr: 384*.8}} GFLOPS || {{#expr: 768*.8}} GFLOPS || {{#expr: 1536*.8}} GFLOPS || {{#expr: 2304*.8}} GFLOPS || {{#expr: 192*.8}} GFLOPS || {{#expr: 384*.8}} GFLOPS || {{#expr: 768*.8}} GFLOPS || {{#expr: 1152*.8}} GFLOPS || {{#expr: 48*.8}} GFLOPS || {{#expr: 96*.8}} GFLOPS || {{#expr: 129*.8}} GFLOPS || {{#expr: 288*.8}} GFLOPS
 +
|-
 +
| Boost (850 MHz) || {{#expr: 384*.85}} GFLOPS || {{#expr: 768*.85}} GFLOPS || {{#expr: 1536*.85}} GFLOPS || {{#expr: 2304*.85}} GFLOPS || {{#expr: 192*.85}} GFLOPS || {{#expr: 384*.85}} GFLOPS || {{#expr: 768*.85}} GFLOPS || {{#expr: 1152*.85}} GFLOPS || {{#expr: 48*.85}} GFLOPS || {{#expr: 96*.85}} GFLOPS || {{#expr: 129*.85}} GFLOPS || {{#expr: 288*.85}} GFLOPS
 +
|-
 +
| Boost (900 MHz) || {{#expr: 384*.9}} GFLOPS || {{#expr: 768*.9}} GFLOPS || {{#expr: 1536*.9}} GFLOPS || {{#expr: 2304*.9}} GFLOPS || {{#expr: 192*.9}} GFLOPS || {{#expr: 384*.9}} GFLOPS || {{#expr: 768*.9}} GFLOPS || {{#expr: 1152*.9}} GFLOPS || {{#expr: 48*.9}} GFLOPS || {{#expr: 96*.9}} GFLOPS || {{#expr: 129*.9}} GFLOPS || {{#expr: 288*.9}} GFLOPS
 +
|-
 +
| Boost (950 MHz) || {{#expr: 384*.95}} GFLOPS || {{#expr: 768*.95}} GFLOPS || {{#expr: 1536*.95}} GFLOPS || {{#expr: 2304*.95}} GFLOPS || {{#expr: 192*.95}} GFLOPS || {{#expr: 384*.95}} GFLOPS || {{#expr: 768*.95}} GFLOPS || {{#expr: 1152*.95}} GFLOPS || {{#expr: 48*.95}} GFLOPS || {{#expr: 96*.95}} GFLOPS || {{#expr: 129*.95}} GFLOPS || {{#expr: 288*.95}} GFLOPS
 +
|-
 +
| Boost (1,000 MHz) || {{#expr: 384*1}} GFLOPS || {{#expr: 768*1}} GFLOPS || {{#expr: 1536*1}} GFLOPS || {{#expr: 2304*1}} GFLOPS || {{#expr: 192*1}} GFLOPS || {{#expr: 384*1}} GFLOPS || {{#expr: 768*1}} GFLOPS || {{#expr: 1152*1}} GFLOPS || {{#expr: 48*1}} GFLOPS || {{#expr: 96*1}} GFLOPS || {{#expr: 129*1}} GFLOPS || {{#expr: 288*1}} GFLOPS
 +
|-
 +
| Boost (1,050 MHz) || {{#expr: 384*1.05}} GFLOPS || {{#expr: 768*1.05}} GFLOPS || {{#expr: 1536*1.05}} GFLOPS || {{#expr: 2304*1.05}} GFLOPS || {{#expr: 192*1.05}} GFLOPS || {{#expr: 384*1.05}} GFLOPS || {{#expr: 768*1.05}} GFLOPS || {{#expr: 1152*1.05}} GFLOPS || {{#expr: 48*1.05}} GFLOPS || {{#expr: 96*1.05}} GFLOPS || {{#expr: 129*1.05}} GFLOPS || {{#expr: 288*1.05}} GFLOPS
 +
|-
 +
| Boost (1,100 MHz) || {{#expr: 384*1.1}} GFLOPS || {{#expr: 768*1.1}} GFLOPS || {{#expr: 1536*1.1}} GFLOPS || {{#expr: 2304*1.1}} GFLOPS || {{#expr: 192*1.1}} GFLOPS || {{#expr: 384*1.1}} GFLOPS || {{#expr: 768*1.1}} GFLOPS || {{#expr: 1152*1.1}} GFLOPS || {{#expr: 48*1.1}} GFLOPS || {{#expr: 96*1.1}} GFLOPS || {{#expr: 129*1.1}} GFLOPS || {{#expr: 288*1.1}} GFLOPS
 +
|-
 +
| Boost (1,150 MHz) || {{#expr: 384*1.15}} GFLOPS || {{#expr: 768*1.15}} GFLOPS || {{#expr: 1536*1.15}} GFLOPS || {{#expr: 2304*1.15}} GFLOPS || {{#expr: 192*1.15}} GFLOPS || {{#expr: 384*1.15}} GFLOPS || {{#expr: 768*1.15}} GFLOPS || {{#expr: 1152*1.15}} GFLOPS || {{#expr: 48*1.15}} GFLOPS || {{#expr: 96*1.15}} GFLOPS || {{#expr: 129*1.15}} GFLOPS || {{#expr: 288*1.15}} GFLOPS
 +
|}
 +
</div>
  
 
== Hardware Accelerated Video ==
 
== Hardware Accelerated Video ==
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== Process Technology ==
 
== Process Technology ==
 
{{main|intel/microarchitectures/broadwell#Process_Technology|l1=Broadwell § Process Technology}}
 
{{main|intel/microarchitectures/broadwell#Process_Technology|l1=Broadwell § Process Technology}}
−
Gen9 LP are part of the Skylake SoC die which uses the same [[14 nm process]] used for the Broadwell microarchitecture.
+
Gen9 are part of the Skylake SoC die which uses the same [[14 nm process]] used for the Broadwell microarchitecture.
  
 
== Architecture ==
 
== Architecture ==
−
Gen9 LP presents a large departure from the Gen8 LP and previous architectures.
+
Gen9 presents a large departure from the Gen8 and previous architectures.
  
−
=== Key changes from {{\\|Gen8 LP}} ===
+
=== Key changes from {{\\|Gen8}} ===
 
* Architecture is drastically different
 
* Architecture is drastically different
−
** Gen9 LP is composed of 3 truely independent major components: Display block, Unslice, and the Slice.
+
** Gen9 is composed of 3 truly independent major components: Display block, Unslice, and the Slice.
 +
** Shared Virtual Memory (SVM) improvements
 +
*** Improved cache coherency performance
 
* Unslice
 
* Unslice
 
** Now sits on its own power gating/clock domain
 
** Now sits on its own power gating/clock domain
Line 121: Line 167:
 
** RAW imaging capabilities
 
** RAW imaging capabilities
 
* Slice
 
* Slice
 +
** Floating point atomics (min/max/cmpexch)
 
** L3 Cache
 
** L3 Cache
 
*** Increased to 768 [[KiB]]/slice (up from 576 KiB/slice)
 
*** Increased to 768 [[KiB]]/slice (up from 576 KiB/slice)
Line 130: Line 177:
 
** Multi-plane overlays
 
** Multi-plane overlays
 
** Texture samplers now natively support an NV12 YUV
 
** Texture samplers now natively support an NV12 YUV
 +
** Min/max texture filtering
 
** Preemption of execution is now supported at the thread level
 
** Preemption of execution is now supported at the thread level
 
** Round robin scheduling of threads within an execution unit.
 
** Round robin scheduling of threads within an execution unit.
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** 16-bit floating point capability is improved with native support for denormals and gradual underflow
 
** 16-bit floating point capability is improved with native support for denormals and gradual underflow
 
* L4$
 
* L4$
−
** The [[eDRAM]] is now a side cache instead of an L4$ like it was in {{\\|Gen8 LP}}. (See {{\\|Skylake#eDRAM architectural changes|Skylake §eDRAM architectural changes}} for the reason)
+
** The [[eDRAM]] is now a side cache instead of an L4$ like it was in {{\\|Gen8}}. (See {{\\|Skylake#eDRAM architectural changes|Skylake §eDRAM architectural changes}} for the reason)
 
** Side-cache eDRAM was moved into the system agent adjacent to the display controller
 
** Side-cache eDRAM was moved into the system agent adjacent to the display controller
  
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==== Entire SoC Overview ====
 
==== Entire SoC Overview ====
 
[[File:skylake soc block diagram.svg|900px]]
 
[[File:skylake soc block diagram.svg|900px]]
−
==== Gen9 LP ====
+
==== Gen9 ====
 
This block is for the most common setup, which is GT2 with 24 execution units.
 
This block is for the most common setup, which is GT2 with 24 execution units.
  
Line 147: Line 195:
 
==== Individual Core ====
 
==== Individual Core ====
 
See {{intel|Skylake#Individual_Core|l=arch}}.
 
See {{intel|Skylake#Individual_Core|l=arch}}.
−
 
−
=== Display ===
 
−
{{empty section}}
 
  
 
=== Unslice ===
 
=== Unslice ===
Line 158: Line 203:
  
 
The '''media general-purpose pipeline''' consists of two fixed-function units: Video Front End ('''VFE''') and the '''Thread Spawner''' ('''TS'''). The VFE unit handles the interfacing with the Command Streamer, writes thread payload data into the Unified Return Buffer, as well as prepares threads to be dispatched through TS unit. The VFE unit also contains the hardware '''Variable Length Decode''' ('''VLD''') engine for MPEG-2 video decode. The TS unit is primarily responsible for interfacing with the '''Thread Dispatcher''' ('''TD''') unit which is responsible for spawning new root-node parent threads originated from VFE unit and for spawning child threads (either leaf-node child threads or branch-node parent thread).
 
The '''media general-purpose pipeline''' consists of two fixed-function units: Video Front End ('''VFE''') and the '''Thread Spawner''' ('''TS'''). The VFE unit handles the interfacing with the Command Streamer, writes thread payload data into the Unified Return Buffer, as well as prepares threads to be dispatched through TS unit. The VFE unit also contains the hardware '''Variable Length Decode''' ('''VLD''') engine for MPEG-2 video decode. The TS unit is primarily responsible for interfacing with the '''Thread Dispatcher''' ('''TD''') unit which is responsible for spawning new root-node parent threads originated from VFE unit and for spawning child threads (either leaf-node child threads or branch-node parent thread).
 +
 +
==== Fixed-Function ====
 +
[[File:gen9 multi-format codec (mfx).svg|350px|right]]
 +
* '''Multi-Format Codec''' ('''MFX''')
 +
** HEVC Decode
 +
** Support for HEVC & VP8 in PAK (for encode)
 +
** New fixed function within MFX for real-time  AVC encoding usages
 +
[[File:gen9 video quality engine (vqe).svg|300px|right]]
 +
* '''Video Quality Engine''' ('''VQE''')
 +
** 16-bit processing path
 +
** 5x5 spatial denoise filter
 +
** Local Adaptive Contrast Enhancement (LACE)
 +
** Camera processing features to allow high-resolution raw camera processing
 +
[[File:gen9 scalar and format conv (sfc).svg|250px|right]]
 +
* '''Scalar and Format Conversion''' ('''SFC''')
 +
** Allows for inline format conversion & upscaling or downscaling of imagest
 +
** Can be coupled with decoder to allow high-quality video processing in the FF units in the unslice without utilizing the media sampler in the slices themselves.
  
 
=== 3D Pipeline Stages  ===
 
=== 3D Pipeline Stages  ===
Line 197: Line 259:
  
 
[[File:gen9 eu.svg|600px]]
 
[[File:gen9 eu.svg|600px]]
 +
 +
==== Preemption Granularity ====
 +
Preemption in Gen9 was improved over Gen8 in a number of way. Preemption is important for mullti-tasking system and especially important for improving responsiveness of operations (i.e. the ability to stop and start operations quickly with minimal latency interruption for the end user). In {{\\|Broadwell}} ({{\\|Gen8}}) Intel added support for the ability to stop operations on object-level for 3D workloads such as on a triangle boundary (i.e. beginning of a triangle, between two triangles, between two lines  or points) and be able to preempt and restore back to those operations. In Gen9 Intel added the ability to stop execution units on an instruction boundary and be able to restore them (previously such preemption was only possible at the boundary of a kernel - i.e. the entire kernel execution must take places before preemption was possible). Gen9 added support for thread-group (complete kernel execution) to mid-thread (instruction boundary) for compute workloads:
 +
 +
Example of responsiveness (Source: IDF15)
 +
{| class="wikitable"
 +
! rowspan="2" | Application !! colspan="2" | Thread-Group Preemption !! colspan="2" | Mid-Thread Preemption
 +
|-
 +
| {{intel|Skylake U|U Series|l=core}} || {{intel|Skylake Y|Y Series|l=core}} || {{intel|Skylake U|U Series|l=core}} || {{intel|Skylake Y|Y Series|l=core}}
 +
|-
 +
| Adobe Photoshop || 4-6 ms || 17-22 ms || 300 µs || 800 µs
 +
|-
 +
| Sample App1 || 200-500 ms || 200-500 ms || 300 µs || 280-320 µs
 +
|-
 +
| Sample App2 || 17 ms || 24 ms || 240 µs || 200-430 µs
 +
|}
 +
 +
=== Display ===
 +
The display has a memory interface (supporting high memory bandwidth coming directly to the display sub-system), a front-end that is responsible for sorting and sequencing the requests (as well as handling things such as rotated displays), and display pipes. The display pipes perform input format conversion, multi-plane composition, color conversion, and scaling the result. The final part of the display port are the prot encoders that convert the input form the display pipes to the appropriate standard used (DP/HDMI/eDP). A number of improvements in Gen9 in the display block were done with respect to the display pipes, specifically being able to consume lossless compression directly without doing any extra unnecessary conversion operations. Additionally the pipes now support render compressed surfaces, Y-tiled surfaces, and on the fly 90/270 rotations.
 +
 +
[[File:gen9 display block.svg|650px]]
 +
 +
==== Multiple Display Planes in a Pipe ====
 +
[[File:gen9 display planes pipe.svg|right|550px]]
 +
* Three plane sources + background
 +
** All 3 are independent
 +
** Fixed order (highest priority is plane3, lowest is background)
 +
** Planes can be:
 +
*** YUV video
 +
*** RGB windows/desktop
 +
** Fixed visual priority/blending order
 +
** Color correction of result
 +
** Two 7x5 scalers
 +
*** Bind to individual planes or pipe output
 +
* Intended to support various OS features such as
 +
** Microsoft's MPO (Multiplane overlay support)
 +
** Android's SurfaceFlinger
  
 
== Scalability ==
 
== Scalability ==
Line 202: Line 301:
  
 
=== GT1 (ULP) ===
 
=== GT1 (ULP) ===
−
GT1 is the most compact configuration offering two benefits: reduced cost and reduced power. GT1 is made of 1 slice containing 2 subslices with 6 EUs/subslice for a total of 12 EUs. With the scale-down, GT1 changes the ratio to 6:1 EU:sampler ratio. Note that this does retains the same ratio of 12 texels/clock and 8 pixels/clock at the backend. This configuration is better suited for some of the low power worlkload (e.g. ASTC-LDR+HDR, ETC1/2 compression). Note that software stack remains unchanged compared to the larger models.
+
GT1 is the most compact configuration offering two benefits: reduced cost and reduced power. GT1 is made of 1 slice containing 2 subslices with 6 EUs/subslice for a total of 12 EUs. With the scale-down, GT1 changes the ratio to 6:1 EU:sampler ratio. Note that this does retains the same ratio of 12 texels/clock and 8 pixels/clock at the backend. This configuration is better suited for some of the low power workload (e.g. ASTC-LDR+HDR, ETC1/2 compression). Note that software stack remains unchanged compared to the larger models.
  
 
[[File:gen9 lp gt1 block diagram.svg|600px]]
 
[[File:gen9 lp gt1 block diagram.svg|600px]]
Line 254: Line 353:
 
|FLOPs/Clk - Double Precision, MAD (peak) || 48 || 72 || 92 / 96 || 188 / 192 || 284 / 288
 
|FLOPs/Clk - Double Precision, MAD (peak) || 48 || 72 || 92 / 96 || 188 / 192 || 284 / 288
 
|-
 
|-
−
|Unslice clocking (coupled/decoupled from Cr slice) || coupled || coupled || coupled || coupled || coupled / decoupled
+
|Unslice clocking (coupled/decoupled from Cr slice) || coupled || coupled || coupled || coupled || coupled
 
|-
 
|-
 
|GTI / Ring Interfaces || 1 || 1 || 1 || 1 || 1
 
|GTI / Ring Interfaces || 1 || 1 || 1 || 1 || 1
Line 393: Line 492:
 
|SFC Instances || 1 || 1 || 1 || 1 || 1
 
|SFC Instances || 1 || 1 || 1 || 1 || 1
 
|}
 
|}
 +
 +
== Datasheets ==
 +
=== White Paper ===
 +
* [[:File:The-Compute-Architecture-of-Intel-Processor-Graphics-Gen9-v1d0.pdf|The Compute Architecture of Intel Processor Graphics Gen9]]
 +
 +
===Programmer's Reference Manual===
 +
* [[:File:intel-gfx-prm-osrc-skl-vol01-preface.pdf|Volume 1: Preface]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol02a-commandreference-instructions-huc.pdf|Volume 2a Addendum: Command Reference: Instructions (Command Opcodes) for the HEVC Micro-Controller (HuC)]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol02a-commandreference-instructions.pdf|Volume 2a: Command Reference: Instructions (Command Opcodes)]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol02c-commandreference-registers-part1.pdf|Volume 2c: Command Reference: Registers Part 1 – Registers A through L]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol02c-commandreference-registers-part2.pdf|Volume 2c: Command Reference: Registers Part 2 – Registers M through Z]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol02d-commandreference-structures.pdf|Volume 2d: Command Reference: Structures]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol03-gpu overview.pdf|Volume 3: GPU Overview]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol04-configurations.pdf|Volume 4: Configurations]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol05-memory views.pdf|Volume 5: Memory Views]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol06-command stream programming.pdf|Volume 6: Command Stream Programming]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol07-3d media gpgpu.pdf|Volume 7: 3D-Media-GPGPU]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol08-media vdbox.pdf|Volume 8: Media VDBOX]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol09-media vebox.pdf|Volume 9: Media Video Enhancement (VEBOX) Engine]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol10-hevc.pdf|Volume 10: HEVC Codec Pipeline (HCP)]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol11-blitter.pdf|Volume 11: Blitter]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol12-display.pdf|Volume 12: Display]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol13-mmio.pdf|Volume 13: Memory-mapped Input/Output (MMIO)]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol14-observability.pdf|Volume 14: Observability]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol15-sfc.pdf|Volume 15: Scaler Format Converter (SFC)]]
 +
* [[:File:intel-gfx-prm-osrc-skl-vol16-workarounds 0.pdf|Volume 16: Workarounds]]

Latest revision as of 16:41, 1 November 2018

Edit Values
Gen9 µarch
General Info
Arch TypeGPU
DesignerIntel
ManufacturerIntel
IntroductionAugust 5, 2015
Process14 nm
Succession

Gen9 (Generation 9) is the microarchitecture for Intel's graphics processing unit utilized by Skylake-based microprocessors. Gen9 is the successor to Gen8 used by Broadwell. The Gen9 microarchitecture is designed separately by Intel and then integrated onto the same Skylake SoC die.

Codenames[edit]

iris graphics logo.svg
iris pro graphics logo.svg

Various models support different Graphics Tiers (GT) which provides different levels of performance. Some models also support an additional eDRAM side cache.

Code Name Description
GT1 Contains 1 slice with 12 execution units.
GT2 Contains 1 slice with 24 execution units.
GT3 Contains 2 slices with 48 execution units.
GT3e Contains 2 slices with 48 execution units. Has an additional eDRAM side cache.
Halo (GT4e) Contains 3 slices with 72 execution units. Has an additional eDRAM side cache.

Models[edit]

Gen9 IGP Models Standards
Name Execution Units Tier Series eDRAM Vulkan Direct3D OpenGL OpenCL Metal
Windows Linux Windows Linux HLSL Windows Linux Windows Linux macOS
HD Graphics (Skylake) 12 GT1 Y - 1.0 12 N/A 5.1 4.5 4.5 2.0 2.1
HD Graphics 510 12 GT1 U, S -
HD Graphics 515 24 GT2 Y -
HD Graphics 520 24 GT2 U -
HD Graphics 530 24 GT2 H, S -
HD Graphics P530 24 GT2 H -
Iris Graphics 540 48 GT3e U 64 MiB
Iris Graphics 550 48 GT3e U 64 MiB
Iris Pro Graphics P555 48 GT3e H 128 MiB
Iris Pro Graphics 580 72 GT4e H 128 MiB
Iris Pro Graphics P580 72 GT4e H 128 MiB
Model SKU EUs CPU Stepping[devID 1] GT Stepping[devID 2] Device2 ID[devID 3] GT Device2 ID Revision[devID 4]
HD Graphics 510 SKL 2+1F DT 12 S0 G0 0x1902 0x6
SKL U - ULT 2+1F D0 H0 0x1906 0x7
SKL - H 4+1F D0 H0 0x190B 0x7
HD Graphics 515 SKL Y – ULX 2+2 24 D0 H0 0x191E 0x7
HD Graphics 520 SKL U – ULT 2+2 D0 H0 0x1916 0x7
HD Graphics 530 SKL 4+2 DT R0 G0 0x191B 0x6
SKL 2+2 DT S0 G0 0x1912 0x6
SKL 4+2 DT R0 G0 0x1912 0x6
HD Graphics P530 SKL WKS 4+2 R1 G1 0x191D 0x6
Iris Graphics 540 SKL U – ULT 2+3E (15W) 48 K1 L1 0x1926 0xA
Iris Graphics 550 SKL U - ULT 2+3E (28W) K1 L1 0x1927 0xA
HD Graphics 535 SKL U - ULT 2+3 K1 L1 0x1923 0xA
Iris Pro Graphics P555 SKL Media Server 4+3FE N0 J0 0x192D 0x9
Iris Pro Graphics 580 SKL H Halo 4+4E 72 N0 J0 0x193B 0x9
Iris Pro Graphics P580 SKL WKS 4+4E N0 J0 0x193D 0x9
  1. ↑ The CPU Stepping is the actual CPU design stepping.
  2. ↑ The GT Stepping refers to the GT design stepping.
  3. ↑ The Device2 ID is the PCI device ID that identifies the GT SKU for driver software
  4. ↑ The GT Device2 Revision ID identifies the silicon stepping for driver software.

Performance[edit]

Frequency Peak Performance
  Half Precision   Single Precision   Double Precision
Models 510 515, 520, 530, P530 540, 550, P555 580, P580 510 515, 520, 530, P530 540, 550, P555 580, P580 510 515, 520, 530, P530 540, 550, P555 580, P580
Tiers GT1 GT2 GT3e GT4e GT1 GT2 GT3e GT4e GT1 GT2 GT3e GT4e
Ref (FLOP/clk) 384/cycle 768/cycle 1536/cycle 2304/cycle 192/cycle 384/cycle 768/cycle 1152/cycle 48/cycle 96/cycle 192/cycle 288/cycle
Base (300 MHz) 115.2 GFLOPS 230.4 GFLOPS 460.8 GFLOPS 691.2 GFLOPS 57.6 GFLOPS 115.2 GFLOPS 230.4 GFLOPS 345.6 GFLOPS 14.4 GFLOPS 28.8 GFLOPS 38.7 GFLOPS 86.4 GFLOPS
Base (350 MHz) 134.4 GFLOPS 268.8 GFLOPS 537.6 GFLOPS 806.4 GFLOPS 67.2 GFLOPS 134.4 GFLOPS 268.8 GFLOPS 403.2 GFLOPS 16.8 GFLOPS 33.6 GFLOPS 45.15 GFLOPS 100.8 GFLOPS
Base (400 MHz) 153.6 GFLOPS 307.2 GFLOPS 614.4 GFLOPS 921.6 GFLOPS 76.8 GFLOPS 153.6 GFLOPS 307.2 GFLOPS 460.8 GFLOPS 19.2 GFLOPS 38.4 GFLOPS 51.6 GFLOPS 115.2 GFLOPS
Base (650 MHz) 249.6 GFLOPS 499.2 GFLOPS 998.4 GFLOPS 1497.6 GFLOPS 124.8 GFLOPS 249.6 GFLOPS 499.2 GFLOPS 748.8 GFLOPS 31.2 GFLOPS 62.4 GFLOPS 83.85 GFLOPS 187.2 GFLOPS
Boost (800 MHz) 307.2 GFLOPS 614.4 GFLOPS 1228.8 GFLOPS 1843.2 GFLOPS 153.6 GFLOPS 307.2 GFLOPS 614.4 GFLOPS 921.6 GFLOPS 38.4 GFLOPS 76.8 GFLOPS 103.2 GFLOPS 230.4 GFLOPS
Boost (850 MHz) 326.4 GFLOPS 652.8 GFLOPS 1305.6 GFLOPS 1958.4 GFLOPS 163.2 GFLOPS 326.4 GFLOPS 652.8 GFLOPS 979.2 GFLOPS 40.8 GFLOPS 81.6 GFLOPS 109.65 GFLOPS 244.8 GFLOPS
Boost (900 MHz) 345.6 GFLOPS 691.2 GFLOPS 1382.4 GFLOPS 2073.6 GFLOPS 172.8 GFLOPS 345.6 GFLOPS 691.2 GFLOPS 1036.8 GFLOPS 43.2 GFLOPS 86.4 GFLOPS 116.1 GFLOPS 259.2 GFLOPS
Boost (950 MHz) 364.8 GFLOPS 729.6 GFLOPS 1459.2 GFLOPS 2188.8 GFLOPS 182.4 GFLOPS 364.8 GFLOPS 729.6 GFLOPS 1094.4 GFLOPS 45.6 GFLOPS 91.2 GFLOPS 122.55 GFLOPS 273.6 GFLOPS
Boost (1,000 MHz) 384 GFLOPS 768 GFLOPS 1536 GFLOPS 2304 GFLOPS 192 GFLOPS 384 GFLOPS 768 GFLOPS 1152 GFLOPS 48 GFLOPS 96 GFLOPS 129 GFLOPS 288 GFLOPS
Boost (1,050 MHz) 403.2 GFLOPS 806.4 GFLOPS 1612.8 GFLOPS 2419.2 GFLOPS 201.6 GFLOPS 403.2 GFLOPS 806.4 GFLOPS 1209.6 GFLOPS 50.4 GFLOPS 100.8 GFLOPS 135.45 GFLOPS 302.4 GFLOPS
Boost (1,100 MHz) 422.4 GFLOPS 844.8 GFLOPS 1689.6 GFLOPS 2534.4 GFLOPS 211.2 GFLOPS 422.4 GFLOPS 844.8 GFLOPS 1267.2 GFLOPS 52.8 GFLOPS 105.6 GFLOPS 141.9 GFLOPS 316.8 GFLOPS
Boost (1,150 MHz) 441.6 GFLOPS 883.2 GFLOPS 1766.4 GFLOPS 2649.6 GFLOPS 220.8 GFLOPS 441.6 GFLOPS 883.2 GFLOPS 1324.8 GFLOPS 55.2 GFLOPS 110.4 GFLOPS 148.35 GFLOPS 331.2 GFLOPS

Hardware Accelerated Video[edit]

[Edit] Skylake (Gen9) Hardware Accelerated Video Capabilities
Codec Encode Decode
Profiles Levels Max Resolution Profiles Levels Max Resolution
MPEG-2 (H.262) Main High 1080p (FHD) Main Main, High 1080p (FHD)
MPEG-4 AVC (H.264) High, Main 5.1 2160p (4K) Main, High, SHP, MHP 5.1 2160p (4K)
JPEG/MJPEG Baseline - 16k x 16k Baseline Unified 16k x 16k
HEVC (H.265) Main 5.1 2160p (4K) Main, Main 10 5.1 2160p (4K)
VC-1 ✘ Advanced, Main, Simple 3, High 3840x3840
VP8 Unified Unified - 0 Unified 1080p
VP9 ✘ 0 Unified 2160p (4K)

Process Technology[edit]

Main article: Broadwell § Process Technology

Gen9 are part of the Skylake SoC die which uses the same 14 nm process used for the Broadwell microarchitecture.

Architecture[edit]

Gen9 presents a large departure from the Gen8 and previous architectures.

Key changes from Gen8[edit]

  • Architecture is drastically different
    • Gen9 is composed of 3 truly independent major components: Display block, Unslice, and the Slice.
    • Shared Virtual Memory (SVM) improvements
      • Improved cache coherency performance
  • Unslice
    • Now sits on its own power gating/clock domain
      • Capable of running at higher speeds if the situation allows (irrespective of slice clock)
      • Can allow for pure fixed media alone
    • Higher throughput
    • Tessellator AutoStrip
    • Fixed function video encoder in the Quick Sync engine
    • codec (decode&encode) support for HEVC, VP8, MJPEG
    • RAW imaging capabilities
  • Slice
    • Floating point atomics (min/max/cmpexch)
    • L3 Cache
      • Increased to 768 KiB/slice (up from 576 KiB/slice)
      • Request queue size was increased
  • Subslice
    • Adaptive scalable texture compression (ASTC)
    • 16x multi-sample anti-aliasing (MSAA)
    • Post depth test coverage mask
    • Multi-plane overlays
    • Texture samplers now natively support an NV12 YUV
    • Min/max texture filtering
    • Preemption of execution is now supported at the thread level
    • Round robin scheduling of threads within an execution unit.
    • new native support for the 32-bit float atomics operations of min, max, and compare/exchange.
    • 16-bit floating point capability is improved with native support for denormals and gradual underflow
  • L4$

Block Diagram[edit]

Entire SoC Overview[edit]

skylake soc block diagram.svg

Gen9[edit]

This block is for the most common setup, which is GT2 with 24 execution units.

gen9 lp gt2 block diagram.svg

Individual Core[edit]

See Skylake#Individual_Core.

Unslice[edit]

gen9 lp media pipeline.svg

The Unslice is one of Gen9's major components and is responsible for the fixed-function geometry capabilities, fixed-function media capabilities, and it provides the interface to the memory fabric. One of the big changes in Gen9 is that the Unslice now sits on its own power/clock domain. This change allows the Unslice to operate at its own speed provided higher on-demand performance when desired. This change has a number of other benefits such as being able to turn off the slices (one or more) when they're not used in cases where pure fixed-function media is used. Additionally, the Unslice is now capable of running at a higher clock while the slice can run at a slower clock when the scenario demands it (such as in cases where higher fixed-function geometry or memory demands occur).

The Command Stream (CS) unit manages the the flow of execution for the FF Pipeline (3D Pipeline) and the Media pipelines. The CS unit performs the switching between pipelines and forwarding command streams to the different stages. Data in the pipeline are passed to the next unit using a messaging network. Messages can be passed directly through registers or by using the URB. The Command Stream also manages the allocation of the URB and supports the Constant URB Entry (CURB) function. The Unified Return Buffer (URB) is globally shared and is explicitly addressed. The pipeline's fixed-function blocks have both read and write access to the URB, additionally the shader cores have write access to the URB.

The media general-purpose pipeline consists of two fixed-function units: Video Front End (VFE) and the Thread Spawner (TS). The VFE unit handles the interfacing with the Command Streamer, writes thread payload data into the Unified Return Buffer, as well as prepares threads to be dispatched through TS unit. The VFE unit also contains the hardware Variable Length Decode (VLD) engine for MPEG-2 video decode. The TS unit is primarily responsible for interfacing with the Thread Dispatcher (TD) unit which is responsible for spawning new root-node parent threads originated from VFE unit and for spawning child threads (either leaf-node child threads or branch-node parent thread).

Fixed-Function[edit]

gen9 multi-format codec (mfx).svg
  • Multi-Format Codec (MFX)
    • HEVC Decode
    • Support for HEVC & VP8 in PAK (for encode)
    • New fixed function within MFX for real-time AVC encoding usages
gen9 video quality engine (vqe).svg
  • Video Quality Engine (VQE)
    • 16-bit processing path
    • 5x5 spatial denoise filter
    • Local Adaptive Contrast Enhancement (LACE)
    • Camera processing features to allow high-resolution raw camera processing
gen9 scalar and format conv (sfc).svg
  • Scalar and Format Conversion (SFC)
    • Allows for inline format conversion & upscaling or downscaling of imagest
    • Can be coupled with decoder to allow high-quality video processing in the FF units in the unslice without utilizing the media sampler in the slices themselves.

3D Pipeline Stages[edit]

Pipeline Stage Functions Performed
Command Stream (CS) The Command Stream stage is responsible for managing the 3D pipeline and passing commands down the pipeline. In addition, the CS unit reads “constant data” from memory

buffers and places it in the URB. Note that the CS stage is shared between the 3D, GPGPU and Media pipelines.

Vertex Fetch (VF) The Vertex Fetch stage, in response to 3D Primitive Processing commands, is responsible for reading vertex data from memory, reformatting it, and writing the results into Vertex URB Entries. It then outputs primitives by passing references to the VUEs down the pipeline.
Vertex Shader (VS) The Vertex Shader stage is responsible for processing (shading) incoming vertices by passing them to VS threads.
Hull Shader (HS) The Hull Shader is responsible for processing (shading) incoming patch primitives as part of the tessellation process.
Tessellation Engine (TE) The Tessellation Engine is responsible for using tessellation factors (computed in the HS stage) to tessellate U,V parametric domains into domain point topologies.

Domain Shader (DS) The Domain Shader stage is responsible for processing (shading) the domain points (generated by the TE stage) into corresponding vertices.

Geometry Shader (GS) The Geometry Shader stage is responsible for processing incoming objects by passing each object’s vertices to a GS thread.
Stream Output Logic (SOL) The Stream Output Logic is responsible for outputting incoming object vertices into Stream Out Buffers in memory.
Clipper (CLIP) The Clipper stage performs Clip Tests on incoming objects and clips objects if required. Objects are clipped using fixed-function hardware
Strip/Fan (SF) The Strip/Fan stage performs object setup. Object setup uses fixed-function hardware.
Windower/Masker (WM) The Windower/Masker performs object rasterization and determines visibility coverage

Slice[edit]

Slices are a cluster of subslices. For most configurations in Gen9, 3 subslices are aggregated into 1 slice to form a total of 24 execution units (depending on the model, some low end models do have less). The slice incorporates the thread dispatch routine, level 3 cache (L3$), a highly banked shared local memory structure, fixed function logic for atomics and barriers, and a number of fixed-function units for various media capabilities. The Global Thread Dispatcher (GTD) is responsible for load balancing thread distribution across the entire device. The global thread dispatcher works in concert with local thread dispatchers in each subslice.

Execution Unit (EU)[edit]

The Execution Units (EUs) are the programmable shader units - each one is an independent computational unit used for execution of 3D shaders, media, and GPGPU kernels. Internally, each unit is hardware multi-threaded capable of executing multi-issue SIMD operations. Execution is multi-issue per clock to pipelines capable of integer, single and double precision floating point operations, SIMD branch capability, logical operations, transcendental operations, and other miscellaneous operations. Communication between the EUs and the support units (shared function units such as operations involving texture sampling or scatter/gather load/stores) is done via messages that were programmatically constructed. Dependency hardware allows threads to sleep until the requested data is returned from those units.

Shared Functions are hardware units that provide a set of specialized supplemental functionality for the EUs. As their name implies they implement functions with insufficient demand to justify the cost of being implemented in the individual EUs. Functionality in these units are shared among the EUs in the subslice. Communication between the EUs and the Shared Function is done via lightweight message passing. Messages are a small self-contained packet of information created by a kernel and directed to a specific shared function. EU threads awaiting the return of a message from the Shared Function unit go into temporary sleep.

The Execution Unit is composed of 7 threads. Each thread has 128 SIMD-8 32-bit registers in a General-Purpose Register File (GRF) and supporting architecture specific registers (ARF). The EU can co-issue to four instruction processing units, including two FPUs, a branch unit, and a message send unit.

gen9 eu.svg

Preemption Granularity[edit]

Preemption in Gen9 was improved over Gen8 in a number of way. Preemption is important for mullti-tasking system and especially important for improving responsiveness of operations (i.e. the ability to stop and start operations quickly with minimal latency interruption for the end user). In Broadwell (Gen8) Intel added support for the ability to stop operations on object-level for 3D workloads such as on a triangle boundary (i.e. beginning of a triangle, between two triangles, between two lines or points) and be able to preempt and restore back to those operations. In Gen9 Intel added the ability to stop execution units on an instruction boundary and be able to restore them (previously such preemption was only possible at the boundary of a kernel - i.e. the entire kernel execution must take places before preemption was possible). Gen9 added support for thread-group (complete kernel execution) to mid-thread (instruction boundary) for compute workloads:

Example of responsiveness (Source: IDF15)

Application Thread-Group Preemption Mid-Thread Preemption
U Series Y Series U Series Y Series
Adobe Photoshop 4-6 ms 17-22 ms 300 µs 800 µs
Sample App1 200-500 ms 200-500 ms 300 µs 280-320 µs
Sample App2 17 ms 24 ms 240 µs 200-430 µs

Display[edit]

The display has a memory interface (supporting high memory bandwidth coming directly to the display sub-system), a front-end that is responsible for sorting and sequencing the requests (as well as handling things such as rotated displays), and display pipes. The display pipes perform input format conversion, multi-plane composition, color conversion, and scaling the result. The final part of the display port are the prot encoders that convert the input form the display pipes to the appropriate standard used (DP/HDMI/eDP). A number of improvements in Gen9 in the display block were done with respect to the display pipes, specifically being able to consume lossless compression directly without doing any extra unnecessary conversion operations. Additionally the pipes now support render compressed surfaces, Y-tiled surfaces, and on the fly 90/270 rotations.

gen9 display block.svg

Multiple Display Planes in a Pipe[edit]

gen9 display planes pipe.svg
  • Three plane sources + background
    • All 3 are independent
    • Fixed order (highest priority is plane3, lowest is background)
    • Planes can be:
      • YUV video
      • RGB windows/desktop
    • Fixed visual priority/blending order
    • Color correction of result
    • Two 7x5 scalers
      • Bind to individual planes or pipe output
  • Intended to support various OS features such as
    • Microsoft's MPO (Multiplane overlay support)
    • Android's SurfaceFlinger

Scalability[edit]

Gen9 can scale from 1 to 3 slices producing SKUs ranging from 12 to 72 execution units (note that the 12 EUs are formed from half a slice effectively).

GT1 (ULP)[edit]

GT1 is the most compact configuration offering two benefits: reduced cost and reduced power. GT1 is made of 1 slice containing 2 subslices with 6 EUs/subslice for a total of 12 EUs. With the scale-down, GT1 changes the ratio to 6:1 EU:sampler ratio. Note that this does retains the same ratio of 12 texels/clock and 8 pixels/clock at the backend. This configuration is better suited for some of the low power workload (e.g. ASTC-LDR+HDR, ETC1/2 compression). Note that software stack remains unchanged compared to the larger models.

gen9 lp gt1 block diagram.svg

GT1.5[edit]

GT1.5, offers 3 subslices of 6 EUs each for a total of 18 EUs.

gen9 lp gt1.5 block diagram.svg

GT2[edit]

GT2 is the standard configuration consisting of 1 slice with 3 subslices and 8 EU/subslice for a total of 24 EUs.

gen9 lp gt2 block diagram.svg

GT3[edit]

GT3 consists of 2 slices with 3 subslices in each and 8 EU/subslice for a total of 48 EUs.

gen9 lp gt3 block diagram.svg

Halo (GT4)[edit]

Codename Halo (GT4) is the most complex configuration offering the highest execution units count. Halo incorporates 3 slices with 3 subslices/slice and 8 EU/subslice for a total of 72 EUs.

gen9 lp gt4 block diagram.svg

Configuration[edit]

Configuration Attribute (Source: Intel's Programmer's Ref Manual)
Attribute Model
GT1F
(1x2x6) 		GT1.5F
(1x3x6) 		GT2
(1x3x8) 		GT3
(2x3x8) 		GT4
(3x3x8)
Global Attributes
Slice count 1 1 1 2 3
Subslice Count 2 3 3 6 9
EU/Subslice 6 6 8 8 8
EU count (total) 12 18 24 48 72
Thread Count 7 7 7 7 7
Thread Count (Total) 84 126 161 / 168 329 / 336 497 / 504
FLOPs/Clk - Half Precision, MAD (peak) 384 576 736 / 768 1504 / 1536 2272 / 2304
FLOPs/Clk - Single Precision, MAD (peak) 192 288 368 / 384 752 / 768 1136 / 1152
FLOPs/Clk - Double Precision, MAD (peak) 48 72 92 / 96 188 / 192 284 / 288
Unslice clocking (coupled/decoupled from Cr slice) coupled coupled coupled coupled coupled
GTI / Ring Interfaces 1 1 1 1 1
GTI bandwidth (bytes/unslice-clk) 64: R
64: W 		64: R
64: W 		64: R
64: W 		64: R
64: W 		64: R
64: W
eDRAM Support N/A N/A N/A 0, 64 MiB 0, 128 MiB
Graphics Virtual Address Range 48 bit 48 bit 48 bit 48 bit 48 bit
Graphics Physical Address Range 39 bit 39 bit 39 bit 39 bit 39 bit
Caches & Dedicated Memories
L3 Cache, total size (bytes) 384K 768K 768K 1536K 2304K
L3 Cache, bank count 2 4 4 8 12
L3 Cache, bandwidth (bytes/clk) 2x 64: R
2x 64: W 		4x 64: R
4x 64: W 		4x 64: R
4x 64: W 		8x 64: R
8x 64: W 		12x 64: R
12x 64: W
L3 Cache, D$ Size (Kbytes) 192K - 256K 512K 512K 1024K 1536K
URB Size (kbytes) 128K - 192K 384K 384K 768K 1008K
SLM Size (kbytes) 0, 128K 0, 192K 0, 192K 0, 384K 0, 576K
LLC/L4 size (bytes) ~2MiB/CPU core ~2MiB/CPU core ~2MiB/CPU core ~2MiB/CPU core ~2MiB/CPU core
Instruction Cache (IC, bytes) 2x 48K 3x 48K 3x 48K 6x 48K 9x 48K
Color Cache (RCC, bytes) 24K 24K 24K 2x 24K 3x 24K
MSC Cache (MSC, bytes) 16K 16K 16K 2x 16K 3x 16K
HiZ Cache (HZC, bytes) 12K 12K 12K 2x 12K 2x 12K
Z Cache (RCZ, bytes) 32K 32K 32K 2x 32K 3x 32K
Stencil Cache (STC, bytes) 8K 8K 8K 2x 8K 3x 8K
Instruction Issue Rates
FMAD, SP (ops/EU/clk) 8 8 8 8 8
FMUL, SP (ops/EU/clk) 8 8 8 8 8
FADD, SP (ops/EU/clk) 8 8 8 8 8
MIN,MAX, SP (ops/EU/clk) 8 8 8 8 8
CMP, SP (ops/EU/clk) 8 8 8 8 8
INV, SP (ops/EU/clk) 2 2 2 2 2
SQRT, SP (ops/EU/clk) 2 2 2 2 2
RSQRT, SP (ops/EU/clk) 2 2 2 2 2
LOG, SP (ops/EU/clk) 2 2 2 2 2
EXP, SP (ops/EU/clk) 2 2 2 2 2
POW, SP (ops/EU/clk) 1 1 1 1 1
IDIV, SP (ops/EU/clk) 1-6 1-6 1-6 1-6 1-6
TRIG, SP (ops/EU/clk) 2 2 2 2 2
FDIV, SP (ops/EU/clk) 1 1 1 1 1
Load/Store
Data Ports (HDC) 2 3 3 6 9
L3 Load/Store (bytes/clk) 2x 64 3x 64 3x 64 6x 64 9x 64
SLM Load/Store (bytes/clk) 2x 64 3x 64 3x 64 6x 64 9x 64
Atomic Inc, 32b - sequential addresses (bytes/clk) 2x 64 3x 64 3x 64 6x 64 9x 64
Atomic Inc, 32b - same address (bytes/clk) 2x 4 3x 4 3x 4 6x 4 9x 4
Atomic CmpWr, 32b - sequential addresses (bytes/clk) 2x 32 3x 32 3x 32 6x 32 9x 32
Atomic CmpWr, 32b - same address (bytes/clk) 2x 4 3x 4 3x 4 6x 4 9x 4
3D Attributes
Geometry pipes 1 1 1 1 1
Samplers (3D) 2 3 3 6 9
Texel Rate, point, 32b (tex/clk) 8 12 12 24 36
Texel Rate, point, 64b (tex/clk) 8 12 12 24 36
Texel Rate, point, 128b (tex/clk) 8 12 12 24 36
Texel Rate, bilinear, 32b (tex/clk) 8 12 12 24 36
Texel Rate, bilinear, 64b (tex/clk) 8 12 12 24 36
Texel Rate, bilinear, 128b (tex/clk) 2 3 3 6 9
Texel Rate, trilinear, 32b (tex/clk) 4 6 6 12 18
Texel Rate, trilinear, 64b (tex/clk) 2 3 3 6 9
Texel Rate, trilinear, 128b (tex/clk) 1 1.5 1.5 3 4.5
Texel Rate, aniso 2x, 32b (tex/clk) 2 3 3 6 9
Texel Rate, aniso 4x, 32b (tex/clk) 1 1.5 1.5 3 4.5
Texel Rate, ansio 8x, 32b (tex/clk) 0.5 0.75 0.75 1.5 2.25
Texel Rate, ansio 16x, 32b (tex/clk) 0.25 0.375 0.375 0.75 1.125
HiZ Rate, (ppc) 64 64 64 2x 64 3x 64
IZ Rate, (ppc) 16 16 16 2x 16 3x 16
Stencil Rate (ppc) 64 64 64 2x 64 3x 64
Pixel Rate, fill, 32bpp (pix/clk, RCC hit) 8 8 8 16 24
Pixel Rate, blend, 32bpp (p/clk, RCC hit) 8 8 8 16 24
Media Attributes
Samplers (media) 2 3 3 6 9
VDBox Instances 1 1 1 2 2
VEBox Instances 1 1 1 2 2
SFC Instances 1 1 1 1 1

Datasheets[edit]

White Paper[edit]

Programmer's Reference Manual[edit]

Retrieved from "https://en.wikichip.org/w/index.php?title=intel/microarchitectures/gen9&oldid=83782"
Facts about "Gen9 - Microarchitectures - Intel"
RDF feed
codenameGen9 +
designerIntel +
first launchedAugust 5, 2015 +
full page nameintel/microarchitectures/gen9 +
instance ofmicroarchitecture +
manufacturerIntel +
microarchitecture typeGPU +
nameGen9 +
process14 nm (0.014 μm, 1.4e-5 mm) +