Latest revision as of 10:15, 22 September 2018

PEZY-SC2 (PEZY Super Computer 2) is a third generation many-core microprocessor developed by PEZY and introduced in early 2017. This chip, which operates at 1 GHz, incorporates 2,048 cores dissipating 180 W. The PEZY-SC2 powers the ZettaScaler-2.x series of supercomputers.

Overview[edit]

Introduced by PEZY along with their second-generation ZettaScaler-2.0 supercomputer series, the SC2 incorporates 2,048 cores along with 8-way SMT support for a total of 16,384 threads, twice as many cores as its predecessor. The PEZY-SC2 powers many of the top Green500 most efficient supercomputers with upward of 14 GFLOPS/watt in performance.

Operating at 1 GHz, the PEZY-SC2 has a peak performance of 8.192 TFLOPS (single-precision) and 4.1 TFLOPS (double-precision) while consuming around 180 Watts. The PEZY-SC2 is designed using over 2.4 billion gates and is manufactured on TSMC's 16FF+ process.

In attempt to increase adaptability in the field of deep learning and AI as well as to increase throughput for specialized workloads, the PEZY-SC2 introduced support for 16-bit half precision floating point support. At 1 GHz, the SC2 can peak at 16.4 TFLOPS for half precision.

Architecture[edit]

Managing the tiny PEZY cores are six P-Class P6600 MIPS (MIPS64R6) processors. Previously, the PEZY-SC relied on two lightweight ARM926 cores that proved to be too much of a performance bottleneck. The SC2 got rid of the four "Prefecture" units that incorporated 256 cities along with 2 MiB of L3 cache. Instead, the SC2 now has 40 MiB of shared last level cache shared not only by all the cities, but also by the MIPS cores. In order to improve performance further, the MIPS cores and the PEZY cores now share the same address space, reducing data transfer overhead. It's worth noting that the use of powerful MIPS cores mean they no longer require to rely on an external Intel Xeon E5 host processor.

Cache[edit]

The SC2 a hexa-core MIPS P6600 process which has its own separate cache:

[Edit/Modify Cache Info]

Cache Organization Cache is a hardware component containing a relatively small and extremely fast memory designed to speed up the performance of a CPU by preparing ahead of time the data it needs to read from a relatively slower medium such as main memory. The organization and amount of cache can have a large impact on the performance, power consumption, die size, and consequently cost of the IC. Cache is specified by its size, number of sets, associativity, block size, sub-block size, and fetch and write-back policies. Note: All units are in kibibytes and mebibytes.

L1$ 768 KiB 786,432 B 0.75 MiB L1I$ 384 KiB 393,216 B 0.375 MiB 6x64 KiB 4-way set associative   L1D$ 384 KiB 393,216 B 0.375 MiB 6x64 KiB 8-way set associative   L2$ 2 MiB 2,048 KiB 2,097,152 B 0.00195 GiB     1x2 MiB 8-way set associative

The SC2 integrates a multi-level cache hierarchy:

[Edit/Modify Cache Info]

Cache Organization Cache is a hardware component containing a relatively small and extremely fast memory designed to speed up the performance of a CPU by preparing ahead of time the data it needs to read from a relatively slower medium such as main memory. The organization and amount of cache can have a large impact on the performance, power consumption, die size, and consequently cost of the IC. Cache is specified by its size, number of sets, associativity, block size, sub-block size, and fetch and write-back policies. Note: All units are in kibibytes and mebibytes.

L1$ 12 MiB 12,288 KiB 12,582,912 B L1I$ 8 MiB 8,192 KiB 8,388,608 B       L1D$ 4 MiB 4,096 KiB 4,194,304 B       L2$ 12 MiB 12,288 KiB 12,582,912 B 0.0117 GiB L3$ 40 MiB 40,960 KiB 41,943,040 B 0.0391 GiB     1x40 MiB shared LLC

Additionally, there is another 40 MiB consisting of 20 KiB per PE of scratch pad memory. This was increased from 16 KiB in the Pezy-SC.

Memory controller[edit]

For main memory, the PEZY-SC2 supports 4 channels of 64-bit DDR4-3200 memory with ECC support for a total aggregated bandwidth of 95.37 GiB/s

[Edit/Modify Memory Info]

	Integrated Memory Controller
	Max Type DDR4-3200 Supports ECC Yes Max Mem 123 GiB Controllers 4 Channels 4 Width 64 bit Max Bandwidth 95.37 GiB/s 97,658.88 MiB/s 102.403 GB/s 102,402.758 MB/s 0.0931 TiB/s 0.102 TB/s Bandwidth Single 23.84GiB/s Double 47.68 GiB/s Quad 95.37 GiB/s

In addition to main memory bandwidth, the PEZY-SC2 supports Wide-IO with a width of 1,024 bit. The SC2 uses ThruChip Interface (TCI), a wireless near-field inductive coupling technology, in order to communicate with the TCI-DRAM chips which are packaged together. The SC2 features four TCI-DRAM interfaces, each providing a maximum bandwidth of 500 GB/s for a total aggregated bandwidth of 2 TB/s.

[Edit/Modify Memory Info]

	Integrated Memory Controller
	Memory Wide I/O Rate 2,000 MHz Width 1,024 bit Channels 4 Max Bandwidth 1.863 TiB/s 1,907.712 GiB/s 1,953,497.088 MiB/s 2,048.39 GB/s 2,048,390.163 MB/s 2.048 TB/s

Expansions[edit]

The SC2 upgraded the PCIe interface to Gen4, supporting up to 64 GB/s. The number of lanes remain unchanged from the PEZY-SC, at 32.

[Edit/Modify Expansions Info]

	Expansion Options
PCIe Revision: 4.0 Max Lanes: 32 Configuration: 4x8, 2x16

See also[edit]

• The 2,048-core PEZY-SC2 sets a Green500 record - WikiChip Fuse