Trying out PRP-CF but I want prime95 to randomly use all threads despite only setting to run on 3. Machine is a 4C/8T. Basically I would like to see the same behaviour (lower temperatures) when I ran LLR with -3 threads. Is it possible?

Question about throttling
 

I installed Prime95 v29.4 b8 on a Toshiba laptop (2 phyical cores, 2.6GHz, Intel 4xxx family) to sunsome PRPs on small numbers.

I noticed that after the first 10,000 iterations, the ms/iter- value grew of about 60%. I thought it was a heating issue (the laptop is thin and the PSU is quite light).

I decided to give a try to the Throttle=n prameter inside prime.txt file, with n=50, 60 and 30.

The best ms/iter. values re achieved using n=30 (1.7 using 2 cores on a 5,9xx,xxx exponent). The ETA value decreased accordingly. Unfortunately, I also noticed that the wallclock time required to complete 10,000 iterations was not 17 seconds (1.7 ms x 10,000) but about 60 seconds (17*0.30).

am I right in stating that the Throttle=n parameter runs the program for n% of the total time, but the ms/iter and ETA values are computed as there were no slowdown?

Luigi
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[QUOTE=ET_;495322]
am I right in stating that the Throttle=n parameter runs the program for n% of the total time, but the ms/iter and ETA values are computed as there were no slowdown?
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That sounds correct.

Throttle may be hard on the CPU. It runs flat out for 1.7ms then idles for 3.5ms.

Instead of throttling in Prime95, you can try the Throttlestop program:
[url]https://www.techpowerup.com/download/techpowerup-throttlestop/[/url]

It will prevent your laptop from throttling but then you have to watch the temperature in the beginnning and lower the multiplier until you reach a speed where it does not overheat. But it has nice builtin view of cpu core temperatures.

I'm still using version 6.00 so I do not know if version 8.60 is good.

[QUOTE=Prime95;495335]That sounds correct.

Throttle may be hard on the CPU. It runs flat out for 1.7ms then idles for 3.5ms.[/QUOTE]
I remember seeing prime95's throttling behavior run the cores hard for many seconds and then give them a break, with chip temp changing by more than 10C each time. Now that would be hard on a cpu,all that substantial thermal cycling. Could well have been an earlier release because I saw it on this 8 year old laptop (which still has the original cpu in it).

[QUOTE=kriesel;495376]I remember seeing prime95's throttling behavior run the cores hard for many seconds and then give them a break, with chip temp changing by more than 10C each time. Now that would be hard on a cpu,all that substantial thermal cycling. Could well have been an earlier release because I saw it on this 8 year old laptop (which still has the original cpu in it).[/QUOTE]

Your recollection is likely correct. It has been a long time since I looked at that undoc.txt feature. I'm thinking it should be deprecated in a future release.

[QUOTE=Prime95;495380]Your recollection is likely correct. It has been a long time since I looked at that undoc.txt feature. I'm thinking it should be deprecated in a future release.[/QUOTE]
What I currently see, with Win64 prime95 V29.4b8, running an ecm curve stage 2, in cpuid HWmonitor 1.35, is 82+-1C, much better I think for thermal stress fatigue on components. I hope this throttling feature remains available for the foreseeable future. I have my 8 year old laptop throttled to 30% and it's running 12W of its nominal 25W TDP. It seems to be gradually deteriorating as I recall using 40-45% throttling a couple years ago, and now it occasionally goes to thermal shutdown when some other intensive activity occurs alongside prime95 at 30%.

From undoc.txt in 29.4b8:

[QUOTE]If you want to run the program on several machines this is typically done
by carrying the program and files around on portable media such as a floppy
or USB memory stick. In this case, you need to defeat the program's
automatic detection of hardware changes. To do this, in prime.txt set
FixedHardwareUID=1[/QUOTE]

If I use this on AWS EC2 instance on startup it still says "CPU identity mismatch" and "ComputerGUID=" in local.txt changes and it creates another CPU on my account. That way you get tons of CPUs on your account, a new one every time you loose your session and it automatically starts a new one.

I'm also wondering what is "HardwareGUID=" in prime.txt compared to "ComputerGUID=" in local.txt? There is also a "WindowsGUID=" in prime.txt but it has no value.

[QUOTE=ATH;495447]
If I use this on AWS EC2 instance on startup it still says "CPU identity mismatch" and "ComputerGUID=" in local.txt changes and it creates another CPU on my account. That way you get tons of CPUs on your account, a new one every time you loose your session and it automatically starts a new one.

I'm also wondering what is "HardwareGUID=" in prime.txt compared to "ComputerGUID=" in local.txt? There is also a "WindowsGUID=" in prime.txt but it has no value.[/QUOTE]

I never did figure out a good solution to this.

I just go to the [URL="https://www.mersenne.org/cpus/"]user account CPUs page[/URL] once in a while and and clean out the old missing-in-action red-lined records.

But now I notice that that "Merge checked CPUs" has a "date override" checkbox, that seems to be new. So now instead of deleting those old records, I guess you can just merge them together. That used to be impossible because of date conflicts, it didn't want you to merge machines that were running simultaneously.

"date override" seems to work, so that is an option. But it would be nice if we could avoid the creation of new CPUs.

I am doing some ECM/P-1 work on numbers of the form b^n+-1. Some of these numbers have known small factors.

When I use a large B1 -- most of these small factors are found in the B1 stage and the B2 stage is skipped.

Is this a bug or is there a way to force the program to do the B2 work despite finding a factor in B1?

Thanks.