3 ms·

To a certain extent it's always been about bandwidth. Everyone is using the same memory technology.

by djmips 6y ago

dragontamer 6y ago
Fujitsu's previous "K" supercomputer was #1 on TOP500 and GREEN500 when it came out. Heck, it was #1 on Green500 for many, many years after its release. K held #1 on HPCG from 2011 through 2018. Fujitsu just has good tech. Its kind of mysterious since its aimed at the Japanese market instead of the US market, so we don't hear much about it. But its clearly a world-class processor company.
- linksnapzz 6y ago
  My impression is that the Fujitsu K-machine && NEC SX-ACE equipment is designed, built, and sold almost exclusively for the Japanese market; courtesy of massive subsidies from the Japanese gov’t for the purpose of maintaining that expertise in-country.
  - gnufx 6y ago
    K was basically a one-off, but you could buy systems with similar technology, though they weren't common outside Japan. A64FX machines are appearing in the West now. There was a recent substantial award for one to a UK academic/Met Office consortium, in which there's some interest.
    - linksnapzz 6y ago
      Yeah, by K-machine I mean any of the PrimeHPC-FX class systems using SPARC64-V derivatives; I'm sure they sold a few outside Japan, but I don't think that not having the wider global market would've deterred Fujitsu from making them. I know some of Fujitsu's A64 modules were making it into Cray systems as well; isn't that what U. Bristol has?
      - gnufx 6y ago
        I'd forgotten the name PrimeHPC-FX. You would think they'd be worth looking at if you knew about K. I don't remember exactly what Bristol have got now. (Its not so easy to get detailed info on UK Tier 2 systems, even if you're supporting one.) I know it's using Infiniband, not Tofu as they're mostly interested in single-node performance for some reason, but I don't know what other than the chips come from Fujitsu. It may be right that they're not doing much with systems. There does seem to be more interest this time round, at least.
gnufx 6y ago
Fugaku, for which A64FX was designed, has no DDR memory, just HBM, but yes because of bandwidth. Its Tofu fabric has decent bandwidth but particularly low latency.

To a certain extent it's always been about bandwidth. Everyone is using the same memory technology.

by djmips 6y ago

To a certain extent it's always been about bandwidth. Everyone is using the same memory technology.

Fujitsu's previous "K" supercomputer was #1 on TOP500 and GREEN500 when it came out. Heck, it was #1 on Green500 for many, many years after its release. K held #1 on HPCG from 2011 through 2018. Fujitsu just has good tech. Its kind of mysterious since its aimed at the Japanese market instead of the US market, so we don't hear much about it. But its clearly a world-class processor company.

linksnapzz 6y ago
My impression is that the Fujitsu K-machine && NEC SX-ACE equipment is designed, built, and sold almost exclusively for the Japanese market; courtesy of massive subsidies from the Japanese gov’t for the purpose of maintaining that expertise in-country.
- gnufx 6y ago
  K was basically a one-off, but you could buy systems with similar technology, though they weren't common outside Japan. A64FX machines are appearing in the West now. There was a recent substantial award for one to a UK academic/Met Office consortium, in which there's some interest.
  - linksnapzz 6y ago
    Yeah, by K-machine I mean any of the PrimeHPC-FX class systems using SPARC64-V derivatives; I'm sure they sold a few outside Japan, but I don't think that not having the wider global market would've deterred Fujitsu from making them. I know some of Fujitsu's A64 modules were making it into Cray systems as well; isn't that what U. Bristol has?
    - gnufx 6y ago
      I'd forgotten the name PrimeHPC-FX. You would think they'd be worth looking at if you knew about K. I don't remember exactly what Bristol have got now. (Its not so easy to get detailed info on UK Tier 2 systems, even if you're supporting one.) I know it's using Infiniband, not Tofu as they're mostly interested in single-node performance for some reason, but I don't know what other than the chips come from Fujitsu. It may be right that they're not doing much with systems. There does seem to be more interest this time round, at least.

gnufx 6y ago

Fugaku, for which A64FX was designed, has no DDR memory, just HBM, but yes because of bandwidth. Its Tofu fabric has decent bandwidth but particularly low latency.