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WuDaoKou µarch
General Info
Arch Type	CPU
Designer	Zhaoxin
Manufacturer	HLMC
Introduction	December 28, 2017
Process	28 nm
Core Configs	2, 4, 8
Pipeline
Type	Superscalar
OoOE	Yes
Speculative	Yes
Reg Renaming	Yes
Instructions
ISA	x86-64
Succession
Zhangjiang LuJiaZui

WuDaoKou is the successor to Zhangjiang, a 28 nm x86 microarchitecture designed by Zhaoxin for mainstream laptops, desktops, and servers.

Brands

Family	Series	Description
KaiXian	KX (5000)	Desktop, Laptops
KaisHeng	KH (20000)	Storage, Servers

 

Release Dates

Development for WuDaoKou started in August 2013. The basic architecture design was completed by June 2014 with basic designed done in July 2015. WuDaoKou logic design was completed in April 2016 and taped out in August 2016. Final verification was done in October 2016 and mass production started in October 2017. The architecture and SKUs were officially unveiled at a conference on December 28, 2018.

Process Technology

WuDaoKou is manufactured on HLMC's 28 nm process.

Architecture

Key changes from Zhangjiang

• 25% higher IPC
• 140% higher performance in multi-threaded workloads
• 8 cores per die (up from 4)
• SoC design
  • New Uncore
    • northbridge moved on-die
    • PCIe 3.0 (from 2.0)
    • DDR4 (From DDR3)
  • New integrated graphics processor
    • HD Audio Output/Codec
    • DirectX 11.1
    • Up to 3 displays
      • DP / eDP / HDMI / VGA
• Core
  • Pipeline was reduced by 5 stages
  • Execution engines were re-balanced
  • Branch prediction unit was reworked and optimized
• FSB removed
  • x4 PCIe 3.0 communication with southbridge chipset
• Chipset
  • Gigabit Ethernet port (RGMII)
  • USB 3.1 Gen2 (Type-C) ports
  • SATA 3.0 ports
• Formal OS certification
  • Windows Hardware Quality Labs (WHQL) certification
    • Windows 7/10

This list is incomplete; you can help by expanding it.

Block Diagram

This section is empty; you can help add the missing info by editing this page.

Memory Hierarchy

• Cache
  • L1D Cache
    • 32 KiB, 8-way set associative
    • Per core
  • L1I Cache
    • 32 KiB, 8-way set associative
    • Per core
  • L2 Cache
    • 4 MiB, 32-way set associative
    • Per quad-core cluster
• System DRAM
  • 2 Channels
  • DDR4, Up to 2400 MT/s

Sockets/Platform

All parts use a HFCBGA 37.5×37.5 mm package and are effectively a system on a chip. However, for the most part, those parts get paired with a chipset which serves as an I/O extension chip. The chipset communicates with the microprocessor over standard PCIe 3.0 x4 lanes.

Chipset
Chipset	TDP	PCIe		SATA	USB			Network	Process	Package
		2.0	3.0	3.0	2.0	3.1 Gen 1	3.1 Gen 2
ZX-200	6 W	9 lanes	-	4	6	3	2	10/100M/1 Gbps	40 nm	FCBGA (21mm x 21mm)

Die

• HLMC 28 nm process
• 187 mm² die size
• 2,100,000,000 transistors

All WuDaoKou Processors

	List of WuDaoKou-based Processors
	Main processor
Model	Family	Launched	Cores	L2	Frequency	Max Memory	ECC
KH-25800	KaisHeng	28 December 2017	8	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	1.8 GHz 1,800 MHz 1,800,000 kHz	128 GiB 131,072 MiB 134,217,728 KiB 137,438,953,472 B 0.125 TiB	✔
KH-26800	KaisHeng	28 December 2017	8	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	2 GHz 2,000 MHz 2,000,000 kHz	128 GiB 131,072 MiB 134,217,728 KiB 137,438,953,472 B 0.125 TiB	✔
KX-5540	KaiXian	28 December 2017	4	4 MiB 4,096 KiB 4,194,304 B 0.00391 GiB	1.8 GHz 1,800 MHz 1,800,000 kHz	64 GiB 65,536 MiB 67,108,864 KiB 68,719,476,736 B 0.0625 TiB	✘
KX-5640	KaiXian	28 December 2017	4	4 MiB 4,096 KiB 4,194,304 B 0.00391 GiB	2 GHz 2,000 MHz 2,000,000 kHz	64 GiB 65,536 MiB 67,108,864 KiB 68,719,476,736 B 0.0625 TiB	✘
KX-U5580	KaiXian	28 December 2017	8	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	1.8 GHz 1,800 MHz 1,800,000 kHz	64 GiB 65,536 MiB 67,108,864 KiB 68,719,476,736 B 0.0625 TiB	✘
KX-U5580M	KaiXian	28 December 2017	8	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	1.8 GHz 1,800 MHz 1,800,000 kHz	64 GiB 65,536 MiB 67,108,864 KiB 68,719,476,736 B 0.0625 TiB	✘
KX-U5680	KaiXian	28 December 2017	8	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	2 GHz 2,000 MHz 2,000,000 kHz	64 GiB 65,536 MiB 67,108,864 KiB 68,719,476,736 B 0.0625 TiB	✘
Count: 7

References

• Information was obtained directly from Zhaoxin
• Zhaoxin launches their highest-performance Chinese x86 chips