Prime95 crashing on ECM with large bounds

IamMusavaRibica · 2022-12-18, 16:21

So yesterday I ran ECM with bounds from few thousand million to around ten billion, came back today and found out prime95 wasn't running anymore. After reopening it, the task continued, it was at curve 1 around 99%, I watched it for five minutes and it crashed again, but it doesn't show any errors and just continues to work when restarted. It's not a cpu or memory problem because i assigned only 20 GB (out of 32) of ram and one and only worker to use only three cpu cores. The program just exits with no error or crash messages. prime.log also doesn't show any error messages. Is this kind of crash normal, especially for large bounds ECM?

Andrew Usher · 2022-12-18, 16:37

Exactly when in the curve did this happen, and were you trying to resume from a savefile?

If the crash happens during stage 2 init, it's surely a memory-allocation issue. Check how much memory it is actually trying to use.

IamMusavaRibica · 2022-12-18, 16:49

Quote:

Originally Posted by Andrew Usher

Exactly when in the curve did this happen, and were you trying to resume from a savefile?

If the crash happens during stage 2 init, it's surely a memory-allocation issue. Check how much memory it is actually trying to use.

Unless stage 2 init should happen while stage 1 is in progress. I'm sure this doesn't have anything to do with stage 2 ECM. But in the unlikely case, how would I fix it? Lower down the memory limit even more?

Andrew Usher · 2022-12-18, 17:15

Stage 2 init doesn't happen when stage 1 is in progress, but immediately after it. However, the Windows icon may still show '99% [or whatever] of stage 1' during it.

SuikaPredator · 2022-12-18, 18:26

Are you using version 30.8 with a very large ECM bound?

I think a possible solution is using version 30.9 for ECM here.

Andrew Usher · 2022-12-18, 19:30

Possibly but he hasn't given enough detail to say. I doubt the potential memory-allocation crashes (which have been present in prime95 ECM for several versions, perhaps from the beginning) have been fixed. Getting it to use less memory, somehow, is the only solution there.

kriesel · 2022-12-18, 21:34

Quote:

Originally Posted by IamMusavaRibica

So yesterday I ran ECM with bounds from few thousand million to around ten billion, came back today and found out prime95 wasn't running anymore. After reopening it, the task continued, it was at curve 1 around 99%, I watched it for five minutes and it crashed again, but it doesn't show any errors and just continues to work when restarted. It's not a cpu or memory problem because i assigned only 20 GB (out of 32) of ram and one and only worker to use only three cpu cores. The program just exits with no error or crash messages. prime.log also doesn't show any error messages. Is this kind of crash normal, especially for large bounds ECM?

Quote:

Originally Posted by Andrew Usher

Possibly but he hasn't given enough detail to say.

Indeed.

Quote:

Originally Posted by kriesel

Make an effort to provide an easily read complete set of the needed context information in the same post with a question or bug report. If you're asking why something is not working how you expect, tell us at the beginning what software you're asking about, what version of the software, what OS you're running it on, what OS version or flavor, what hardware, what computation type (for mprime / prime95, Gpuowl, Mlucas or any other software that can perform more than one computation type), stage if relevant, exponent, bounds or bit levels as applicable, non-default tuning, any parameters it seems to be having difficulties with, and any other pertinent information. If asking about Linux, what version of what distribution. In the case of a GPU related question, include the GPU model, driver name and version, and perhaps hardware specs that are relevant (GPU ram for example, or NVIDIA compute capability level). A little time spent once, providing that info in a convenient format, can save many readers and the original poster a little time each, and reduce the need for Q&A that sometimes follows when such information is missing, or hidden away somewhat in a long code box line. It's especially important to be considerate of the time of the rare few very talented volunteer programmers.

Prime95 · 2022-12-19, 01:40

I just fixed a problem where very high stage 2 bounds caused prime95 to allocate much more memory than allowed. This was in the new prime-pairing code, so it appeared in 30.6 (or was it 30.4 or 30.55?). The fix is to run 30.9 with enough memory that uses the newer stage 2 code or downgrade to 30.3.

2022-12-18, 16:21	#1
IamMusavaRibica Nov 2022 2×3 Posts	Prime95 crashing on ECM with large bounds So yesterday I ran ECM with bounds from few thousand million to around ten billion, came back today and found out prime95 wasn't running anymore. After reopening it, the task continued, it was at curve 1 around 99%, I watched it for five minutes and it crashed again, but it doesn't show any errors and just continues to work when restarted. It's not a cpu or memory problem because i assigned only 20 GB (out of 32) of ram and one and only worker to use only three cpu cores. The program just exits with no error or crash messages. prime.log also doesn't show any error messages. Is this kind of crash normal, especially for large bounds ECM?

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2022-12-18, 16:37	#2
Andrew Usher Dec 2022 3·13² Posts	Exactly when in the curve did this happen, and were you trying to resume from a savefile? If the crash happens during stage 2 init, it's surely a memory-allocation issue. Check how much memory it is actually trying to use.

2022-12-18, 17:15	#4
Andrew Usher Dec 2022 3×13² Posts	Stage 2 init doesn't happen when stage 1 is in progress, but immediately after it. However, the Windows icon may still show '99% [or whatever] of stage 1' during it.

2022-12-18, 18:26	#5
SuikaPredator Aug 2022 China 3C₁₆ Posts	Are you using version 30.8 with a very large ECM bound? I think a possible solution is using version 30.9 for ECM here.

2022-12-18, 19:30	#6
Andrew Usher Dec 2022 773₈ Posts	Possibly but he hasn't given enough detail to say. I doubt the potential memory-allocation crashes (which have been present in prime95 ECM for several versions, perhaps from the beginning) have been fixed. Getting it to use less memory, somehow, is the only solution there.

2022-12-19, 01:40	#8
Prime95 P90 years forever! Aug 2002 Yeehaw, FL 8279₁₀ Posts	I just fixed a problem where very high stage 2 bounds caused prime95 to allocate much more memory than allowed. This was in the new prime-pairing code, so it appeared in 30.6 (or was it 30.4 or 30.55?). The fix is to run 30.9 with enough memory that uses the newer stage 2 code or downgrade to 30.3.