from Hacker News

Can Vector Supercomputing Be Revived?

by jcbeard on 10/27/17, 11:29 AM with 13 comments

• by jcbeard on 10/27/17, 12:07 PM

  Better programmable gather/scatter (like described here: https://www.nextplatform.com/2017/09/14/shedding-light-dark-...) can definitely open up a wider range of applications to vectorization.

• by jabl on 10/28/17, 7:55 AM

  More generally, I'd really like "real" vector ISA's to become mainstream [1]. We've suffered from the scourge of packed-SIMD long enough, thank you very much.

  ARM SVE, RISC-V V extension, and indeed to an extent AVX-512 look pretty good.

  [1] Not saying that every chip must dedicate a huge portion of the die area to a monster vector unit, I'd just like the ISA to be there so programmers and compilers can target it.

• by payne92 on 10/28/17, 1:18 AM

  It’s very very very tough to compete with the economies of scale and ecosystem with modern GPU computing.

  Vector supercomputing doesn’t need to be “revived”, it is already here.

• by davidad_ on 10/28/17, 8:17 AM

  Those mining memory-bandwidth-hard cryptocurrencies, like zcash, may consider evaluating these. According to the article, they’ll have 1200 GB/s, vs 900 GB/s for the top nVidia Volta card. (Of course, it’s quite likely that this increase in memory bandwidth isn’t worth it for reasons of cost, ISA suitability for the particularities of Equihash, etc., but hard to say without a lot of thinking-through.)

• by jdboyd on 10/28/17, 6:27 AM

  I found it fascinating that NEC's new vector machine is now vector accelerator's on PCIe cards. First, this reminds me of how early vector processors were add-ons to existing processors. I wonder if that changes the programming model (compared to the sx-9/ace or cray j90s) and how.

• by mmarx on 10/28/17, 9:12 AM

  Vector engines really suffer from numerical stability problems, so for certain kinds of problems, you'll get wrong answers (but at least you'll get them fast).