Prime95 30.8 (big P-1 changes, see post #551) - Page 68

storm5510 · 2022-09-30, 15:33

Quote:

Originally Posted by kriesel

Yes, and there's empirical evidence that using almost all the dual-CPU-system's ram in prime95 is suboptimal compared to using almost all the near ram on each CPU, in P-1 stage 2, and leaving the rest to be used for the other CPU's processes. Mprime / prime95 needs a little user assistance apparently to ensure it's the near ram in the multi-CPU (not merely multi-core) case.

I believe you are saying there is no efficient or easy way to use both. IMO, this would take some really deep programming on George's part. I do not know that he would want to mess with it.

Off topic: I wish there was a console (Win64) version of Prime95. All the GUI baggage would be gone. I have used and like mprime for this very reason.

kriesel · 2022-09-30, 16:32

Quote:

Originally Posted by storm5510

I believe you are saying there is no efficient or easy way to use both. ... All the GUI baggage would be gone. I have used and like mprime for this very reason.

It's easy to use all cores in one prime95 instance, on a dual-Xeon system. I've been doing that for years. Easy, but maybe not the most throughput. There was a performance dip seen going through 64 GiB ram allowed for P-1 etc on a 128 GiB dual-Xeon machine.

For computing efficiency, for P-1, on a dual-Xeon, I'm using two prime95 instances via the NUMA aware start command, each confined to its own single Xeon package/NUMA node/quad-channel ram access.

Long ago Madpoo reported results for a dual-14-core IIRC, observing a maximum speed of iterations, around 20 cores total.

For George to dive into making prime95, mprime etc, significantly NUMA aware, it would need to be a higher priority than some other choices for his time & talent. I'm not convinced there are enough dual-Xeon machines to justify it, and he hasn't a test machine himself. Right now IIUC he's bringing the polynomial performance to ECM that was in v30.8 introduced for P-1. Maybe P+1 is next? And there's the occasional bug identification and fix, etc.

If you want to run cmd line like mprime, on a Windows system, perhaps you could install WSL on Windows, and run mprime in the Linux environment that provides.

storm5510 · 2022-10-01, 16:52

Quote:

Originally Posted by kriesel

...If you want to run cmd line like mprime, on a Windows system, perhaps you could install WSL on Windows, and run mprime in the Linux environment that provides.

I have WSL1 with Ubuntu 20.04.4 on this system but it is really uncooperative. None of the console commands I use with the dedicated Linux box on another system seem to work here. I know mprime is here somewhere, but it shows no folders when I use "dir." I do not know what its problem is. All of its folders, if there are any, are buried really deep in the OS. They should not be. This makes it difficult to use with something like mfaktc where the work files must be manually edited. So, I do not mess with it.

kriesel · 2022-10-01, 17:31

Better WSL1 than WSL2, for looking at linux data from the Windows side. Don't move or delete it from the Windows side though; that won't handle linux inodes properly, or some such, and makes a mess.
In WSL1, path on the Windows side is probably something analogous to
C:\Users\(Windows-username)\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\home\(Linux-username?)
Find and make shortcut for future reference.

Of course, "dir" won't work at the Ubuntu command line. And neither will Windows paths. (Drive id's, / vs. \, other path differences)

henryzz · 2022-10-02, 11:49

Replace dir with ls

I typically store all my data on the windows drives from wsl2.

storm5510 · 2022-10-02, 16:20

Quote:

Originally Posted by kriesel

Better WSL1 than WSL2, for looking at linux data from the Windows side. Don't move or delete it from the Windows side though; that won't handle linux inodes properly, or some such, and makes a mess.
In WSL1, path on the Windows side is probably something analogous to
C:\Users\(Windows-username)\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\home\(Linux-username?)
Find and make shortcut for future reference.

Of course, "dir" won't work at the Ubuntu command line. And neither will Windows paths. (Drive id's, / vs. \, other path differences)

Too late. I already updated it to WSL2 yesterday evening. I don't see any difference.

I used "Canonical" for a search. I have two sets of folders with this name. See the attached image. One is two years old and another is recent.

I do not want to pull this way off-topic or make it a long drawn-out subject!

kriesel · 2022-10-02, 17:42

Quote:

Originally Posted by kriesel

Error setting affinity to cpuset 0x000000c0: No error
(refer to attachment of https://mersenneforum.org/showpost.p...&postcount=731)

Adding AffinityVerbosity=0 to prime.txt and restarting prime95 did not resolve it.

Prime95 · 2022-10-02, 18:29

Quote:

Originally Posted by kriesel

Adding AffinityVerbosity=0 to prime.txt and restarting prime95 did not resolve it.

What does hwloc report for the configuration when running two prime95s each bound to their own NUMA node?
(run benchmark and quickly stop it, look in results.bench.txt)

kruoli · 2022-10-02, 18:34

The problem is:
kriesel sets the affinities to only one hyperthread per physical core but Prime95 tries to set the workers' affinity to both hyperthreads per core. Since one of them is not available by the OS, the error occurs.

Prime95 · 2022-10-02, 19:22

Quote:

Originally Posted by kruoli

The problem is:
kriesel sets the affinities to only one hyperthread per physical core but Prime95 tries to set the workers' affinity to both hyperthreads per core. Since one of them is not available by the OS, the error occurs.

Why would the OS restrict setting affinity to both logical processors of one physical processor?

kruoli · 2022-10-02, 19:25

If the user has set the affinity by hand, the OS should not give the program the possibility to extend this.

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2022-10-01, 17:31	#741
kriesel "TF79LL86GIMPS96gpu17" Mar 2017 US midwest 3×5×503 Posts	Better WSL1 than WSL2, for looking at linux data from the Windows side. Don't move or delete it from the Windows side though; that won't handle linux inodes properly, or some such, and makes a mess. In WSL1, path on the Windows side is probably something analogous to C:\Users\(Windows-username)\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\home\(Linux-username?) Find and make shortcut for future reference. Of course, "dir" won't work at the Ubuntu command line. And neither will Windows paths. (Drive id's, / vs. \, other path differences)

2022-10-02, 11:49	#742
henryzz Just call me Henry "David" Sep 2007 Liverpool (GMT/BST) 6056₁₀ Posts	Replace dir with ls I typically store all my data on the windows drives from wsl2.

2022-10-02, 18:34	#746
kruoli "Oliver" Sep 2017 Porta Westfalica, DE 1,447 Posts	The problem is: kriesel sets the affinities to only one hyperthread per physical core but Prime95 tries to set the workers' affinity to both hyperthreads per core. Since one of them is not available by the OS, the error occurs.

2022-10-02, 19:25	#748
kruoli "Oliver" Sep 2017 Porta Westfalica, DE 10110100111₂ Posts	If the user has set the affinity by hand, the OS should not give the program the possibility to extend this.