New Linpack Stress Test Released

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crashtech

Lifer
Jan 4, 2013
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I may do some testing when I have time. Thanks for providing this interesting new tool. At first blush the flops (and CPU usage) seem low on my Ryzen 5 1600, but I'll have to use it more and pit it against some Intel stuff to get comparative results.
 

.vodka

Golden Member
Dec 5, 2014
1,203
1,537
136
Can someone test v0.9.2 on Zen and report back?

The unofficial Korean LinX version I linked a few posts back is still faster on Zen. Your patched linpack binaries in v0.9.2 aren't using AVX/2 on Zen for some reason.
 

Regeneration

Member
Nov 3, 2007
55
37
91
www.ngohq.com
A new version is now available.

Both AMD and Intel users should get better scores when benchmarking since Linpack now runs only on real cores.

Threads will now spawn in a more balanced manner when stress testing. Most useful for non-Intel CPUs and MP/DP systems.
 

rvborgh

Member
Apr 16, 2014
195
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101
is there a way of specifying the # of threads prior to the run? On my quad-opteron (48 core) this thing only spawns 12 threads during the benchmark.
 
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rvborgh

Member
Apr 16, 2014
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Interesting, i rebooted and in my SuperMicro BIOS set things to node interleaving On. (ie non NUMA mode - evens out memory latency to all sockets). - 187 GFlops.

With the BIOS set to NUMA mode (ie node interleaving Off)... results were - 148.xx GFlops.

i normally have it set to NUMA for exactly the reasons you mention. i like to have most games sit on socket 1 and use the memory attached to that socket... better latency = higher fps.

Linpack seems to like more memory bandwidth however.

This is with 4 Opteron 61xx series (12 K10 cores each) running at 3.0 GHz. Unfortunately i can't try running at 3.3 since these 92mm Noctuas won't cool fast enough :(

This is the "problem" with MP/DP rigs running Windows. A lot of apps and games use only one CPU because Windows categorizes each CPU separately.
 

AdamK47

Lifer
Oct 9, 1999
15,207
2,838
126
Ran the benchmark to see what I'd get. Only 228 GFlops. Running the stress test with 8 threads and 9.6GB allocated yields this.
AUk1n0d.png
 
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ehume

Golden Member
Nov 6, 2009
1,511
73
91
The benchmark results are comparable with other people. Ryzen 2700X is getting around 180 GFlops.
I would be interested to see someone with an i7 8700k's Linpack Extreme results overclocked. I routinely ran LinX 0.6.5 (Linpack with AVX2 front end) at 5 GHz, but I did not keep track of the Gflops (I was testing heatsinks). I wonder . . .
 

rvborgh

Member
Apr 16, 2014
195
94
101
Its a bit strange. K10 is supposedly capable of 4 DP per cycle - "4 DP FLOPs/cycle: 2-wide SSE2 addition + 2-wide SSE2 multiplication". Yet i am getting nowhere near that.

i'm running 48 K10s at 3.0 GHz... my performance should be approximately 2.5 to 3x what it is (ie at least in the high 400s).

https://www.degruyter.com/downloadpdf/j/comp.2013.3.issue-1/s13537-013-0101-5/s13537-013-0101-5.pdf

^That is exactly what I would expect. 86-87% efficiency, 8 DP ops/clock, 8 cores, 3.8 GHz. Multiply all of it together and it comes to ~210 GFLOP/s.
 
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tamz_msc

Diamond Member
Jan 5, 2017
3,773
3,596
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Its a bit strange. K10 is supposedly capable of 4 DP per cycle - "4 DP FLOPs/cycle: 2-wide SSE2 addition + 2-wide SSE2 multiplication". Yet i am getting nowhere near that.

i'm running 48 K10s at 3.0 GHz... my performance should be approximately 2.5 to 3x what it is (ie at least in the high 400s).

https://www.degruyter.com/downloadpdf/j/comp.2013.3.issue-1/s13537-013-0101-5/s13537-013-0101-5.pdf
Maybe it still needs optimization for older architectures, or this is still not optimized for OpenMP?
 

rvborgh

Member
Apr 16, 2014
195
94
101
new version seems to stress things a bit more and produces marginally better result.

48 K10 cores at 3.0 GHz.

187 GFlops NUMA mode (node interleaving off) up from 148.

250 GFlops non NUMA mode (node interleaving on) up from 187
 

Excessi0n

Member
Jul 25, 2014
140
36
101
This consistently reports a hardware failure within 10-15 minutes on my 8700K when running with 12 threads, seemingly regardless of processor settings. An OC which will happily run the latest Prime95 all day long? Failed. Stock? Failed. An anemic 3GHz at a toasty 1.45 volts? Failed. At this point I figure it must be some sort of bug with the program's error detection.

This behavior disappears when running with the same number of threads as physical cores (6), at which point it seems to be stable at the same settings as the latest Prime95.
 

ehume

Golden Member
Nov 6, 2009
1,511
73
91
This consistently reports a hardware failure within 10-15 minutes on my 8700K when running with 12 threads, seemingly regardless of processor settings. An OC which will happily run the latest Prime95 all day long? Failed. Stock? Failed. An anemic 3GHz at a toasty 1.45 volts? Failed. At this point I figure it must be some sort of bug with the program's error detection.

This behavior disappears when running with the same number of threads as physical cores (6), at which point it seems to be stable at the same settings as the latest Prime95.
I don't know about this new Linpack, but LinX 0.6.5 runs a 12-threaded 8700K for 30min, with no sign of shutting down. I used to run this over and over at various OC's, up to 5 GHz.
 

Regeneration

Member
Nov 3, 2007
55
37
91
www.ngohq.com
This consistently reports a hardware failure within 10-15 minutes on my 8700K when running with 12 threads, seemingly regardless of processor settings. An OC which will happily run the latest Prime95 all day long? Failed. Stock? Failed. An anemic 3GHz at a toasty 1.45 volts? Failed. At this point I figure it must be some sort of bug with the program's error detection.

This behavior disappears when running with the same number of threads as physical cores (6), at which point it seems to be stable at the same settings as the latest Prime95.

Can you post a screenshot?
 

AdamK47

Lifer
Oct 9, 1999
15,207
2,838
126
This consistently reports a hardware failure within 10-15 minutes on my 8700K when running with 12 threads, seemingly regardless of processor settings. An OC which will happily run the latest Prime95 all day long? Failed. Stock? Failed. An anemic 3GHz at a toasty 1.45 volts? Failed. At this point I figure it must be some sort of bug with the program's error detection.

This behavior disappears when running with the same number of threads as physical cores (6), at which point it seems to be stable at the same settings as the latest Prime95.

I can confirm the same behavior on my system.

I've been playing with reduced memory timings for my memory and used Prime95 with 24GB allocated over night for 8 hours and a few hours the night before. I then ran AIDA64 stress test for a few hours today while doing other things. Everything passed. I then decided to try this new "Linpack Xtreme" test again for good measure with all threads. Previously, I've been using 8 threads since that's normally how you would use a Linpack test. It failed quickly with 16 threads. After reading your post I decided to underclock everything and run the test again. It failed the same way. The test failed at 3.8GHz (with all cores utilized) and with the memory at only 2133 with very loose timings. It should pass any test.

ECh0Wgn.png


This utility seemed like a great thing at first. I'm going to have to stop using it and any future release even if there is a fix. There is now huge doubt about its functionality. A stability test should only fail when there is indeed a valid failure. It should not be producing a false positive for instability. I'd recommend others also not use it.