Part 9. CPU SIMD Extension for All (ARM & POWER)

content by Xing Chen

ARM CPU also developed its own SIMD extension, called SVE, short for Scalable Vector Extension, here under its microarchitecture. You don’t need to search everywhere, it is clearly marked “SIMD” in the picture, haven’t you seen the 4x 128bit arithmetic blocks?

https://en.wikichip.org/w/images/2/28/neoverse_v1_block_diagram.svg

Arm licenses processor designs to semiconductor companies that incorporate Arm technology into their computer chips, it doesn’t produce physical CPUs, thus it is a good idea to have a look of the HPC-oriented ARM CPU from Fujitsu: A64FX. https://www.fujitsu.com/global/documents/solutions/business-technology/tc/catalog/20180821hotchips30.pdf

There is a very interesting blog comparing X86 and ARM SIMD, I just read the conclusion not the whole text, but I encourage you to do it: https://blog.yiningkarlli.com/2021/09/neon-vs-sse.html

Don’t worry, the big blue IBM POWER does have a SIMD extension, I let you to find it out from the following slides: https://hc32.hotchips.org/assets/program/conference/day1/HotChips2020_Server_Processors_IBM_Starke_POWER10_v33.pdf

The HPC industry does need this SIMD extension, cause this is the way to improve the performance. I would like to end this post by the following wikipage, which summarized its Pro’s and Con’s, enjoy: https://en.wikipedia.org/wiki/Single_instruction,_multiple_data