Intel Xeon PHI?

[kriesel]

Originally Posted by ewmayer

If someone spots one for under US$500, tho, by all means send up a flare. Could be an interesting mini-build project for next year.

$499 before shipping, taxes, addins. Enclosure, modest PSU, 7210 64-core Xeon Phi with on-chip memory only, US power cord. No HD or OS included. Max add-in memory 6x64G LRDIMM or 6x32G RDIMM. 2x at max speed and density currently costs more than the base system. That will likely change over time. Max 6x64 +16 =400 GB, shy of the 512 GB suggested for F33 P-1, but ample for mersenne.org range.

https://www.ebay.com/itm/Hydra-7210-...c/224194633867
Get em while they last, 2 gone in past hour, 5 remain. (PM me where to send the finder's fee:])
Motherboard specs https://www.supermicro.com/products/..._Phi/K1SPE.cfm

4 Phi 2U alternative $1950 https://www.ebay.com/itm/ASRock-Rack...0/184460467766

Tesla alternative for deep pockets & cold winters, just $7999. https://www.ebay.com/itm/Supermicro-...d/373256448498

[xilman]

Originally Posted by ewmayer

...

He's back!

[VBCurtis]

I'm very interested to hear how the KNL system runs. Thinking about buying one for NFS work- sieving or matrices. Please let me know if you're interested in running a test or two so I can justify such a purchase for speeed!

[ewmayer]

Originally Posted by VBCurtis

I'm very interested to hear how the KNL system runs. Thinking about buying one for NFS work- sieving or matrices. Please let me know if you're interested in running a test or two so I can justify such a purchase for speeed!

I, too, am very interested - actually I have a good idea how fast it should be for my Fermat-work, having hogged many system-days of CPU time on the GIMPS KNL before it went offline and its physical-host went AWOL. Main immediate issue for me will be how tricky the OS/software setup will be - gonna do the simple dumb thing first of attempting install of the same Ubuntu 19.10 image I've used for both my Radeon-VII-hosting systems as well as my 3 little Intel NUCs - if that happens to work in terms of being able to get a GCC Mlucas build and run-on-all-64-cores, we can get straight to testing stuff, happy to try out NFS for you if build&test are straightforward. Note, though, will be sticking to the 16GB of onboard RAM for the moment, so Block Lanczos on huge matrices is out. :)

Speaking of getting-up-and-running, just got e-mail from the KNL seller confirming it lacks onboard WiFi, so time to order a USB WiFi stick and an SSD.

[VBCurtis]

I don't recall if msieve benefits from avx-512; perhaps a pair of compilation attempts, with vbits=256 and 512. Data set would be the one from the msieve benchmark thread- that matrix should be big enough to show Phi scaling up to 32 threads, and I can extrapolate from that test to larger matrices well enough.

The other test I have in mind is to run CADO on RSA-130 with 64 and 128 threads. Either one would run on I=13 (aka 13e equivalent on CADO), so memory use should be small enough for 32 or maybe 64 two-threaded processes to fit in 16GB. If performance scales with raw Ghz like it should for sieving, RSA-130 will take about an hour!

Strongly considering just buying this, and adding RAM later. There's some fun to be had on 16GB, with 6x16GB ram costing about as much as the initial CPU/board/case.

I think I'll wait for you to get ubuntu installed, and maybe wait for a benchmark. Hopefully I'll wait....

[kriesel]

actually I have a good idea how fast it should be for my Fermat-work, having hogged many system-days of CPU time on the GIMPS KN.

Was that a 7210 also? Within 72xx, there's only modest clock rate differences, and core-count differences. 1.3, 1.4, 1.5 Ghz base, 64, 68, 72 cores. All 4-way HT. The bargain box is 1.3, 64, 4xHT. 1.5x72 is only ~1.3 x 1.3x64, not a big jump.

[frmky]

Originally Posted by VBCurtis

I'm very interested to hear how the KNL system runs. Thinking about buying one for NFS work- sieving or matrices. Please let me know if you're interested in running a test or two so I can justify such a purchase for speeed!

Hijacking the thread, KNL works well enough for msieve LA if you are careful. Be sure to put one MPI thread on each tile. Sharing threads across tiles REALLY slows it down. And keep everything in MCDRAM if possible. Going out to DDR4 really slows it down. Of course there's only 16 GB of MCDRAM so that may not be possible with only one node. A few NFS@Home jobs have run on KNL, 2,1063+ being one example that used 8 nodes: https://pastebin.com/Mdj1cyB2

[tServo]

Speaking of the KNL systems, has anyone made a concerted effort to track down David Airsquirrels ? That system was purchased with donations from several forum members ( including me ) and should be retrieved to be used by someone.

[Mark Rose]

AirSquirrels has been updating their Facebook and Instagram, so someone more official than me could inquire with them perhaps.

[Mark Rose]

Support in Linux was just dropped. Make some noise on the mailing list if you want support restored in future kernel.

https://lore.kernel.org/lkml/2020110...kroah.com/T/#u

[ewmayer]

Mod note: I moved/copy/edited the various KNL posts & material which had been posted to the neighboring XFX-4-sale thread to this one.

Originally Posted by Mark Rose

Support in Linux was just dropped. Make some noise on the mailing list if you want support restored in future kernel.

https://lore.kernel.org/lkml/2020110...kroah.com/T/#u

So KNL Linux-kernel support will be gone in the various Linux distros starting when? Immediately? Actually, though I don't really speak Linux-ese at the insier level, the relevant snip from that post seems to be:

The "big" driver removal is the MIC drivers have been asked to be
removed as the hardware never shipped and Intel no longer wants to
maintain something that no one can use. This is welcomed by many as the
DMA usage of these drivers was "interesting" and the security people
were starting to question some issues that were starting to be found in
the codebase.

That refers specifically to hardware which never shipped, which does not apply to KNL. Can you clarify?

Should be moot for me in any event - as noted, I was planning on using a year-old Ubuntu distro for my initial boot attempt - should that fail for some reason there is a more-specific stack recommended by Intel for KNL, have the link saved somewhere.