Software suggestion:

[JuanTutors]

Cheesehead, I gotta say, your negativity on this forum has definitely increased in the years you've been here.

Something that's been consistently true about this forum is, people just type in the first thing that comes to their head without actually responding to the original comment itself.

I'm definitely not the only one whose computer doesn't use the full processor during stage 2 of P-1 factoring, and your use of a very weak deductive fallacy based on something that is inconsequential to the purpose of the post is beneath even the most frequent ranters of us, and is not relevant to that problem or to the proposed solution since the problem as described exists.

OldCpuSpeed=3200
WorkerThreads=2
Affinity=100
ThreadsPerTest=1
Memory=1100 during 6:40-2:10 else 1100
RollingAverage=951
MaxHighMemWorkers=1

[cheesehead]

Is it a correct restatement to say that you've been proposing the theory that:

(a) Prime95 is somehow failing to make its normally high use of your system's CPU time during P-1, and that

(b) this is not due to hardware, the operating system, or the way the prime.txt, local.txt, and/or worktodo.txt are set up

?

- - -

Originally Posted by dominicanpapi82

OldCpuSpeed=3200
WorkerThreads=2
Affinity=100
ThreadsPerTest=1
Memory=1100 during 6:40-2:10 else 1100
RollingAverage=951
MaxHighMemWorkers=1

Okay, explain to me why the evidence you've shown us so far rules out the simple possibility that:

only half of your cores are specified to have Prime95 assignments running on them, which is why your overall system CPU usage is only about 50% even though the P-1 thread uses almost 100% of the core it's running on.

Perhaps I'm mistaken or overlooked something, but I don't see anything you've told us that requires that the answer to your underutilization is any more complicated than that: not enough cores specified to run Prime95 assignments.

What evidence, exactly, in your above posts is incompatible with that possibility?

- - -

One detail I don't yet see: is your system dual-core or quad-core? It seems to me that everything you've posted is compatible with either possibility. (Two threads could be running on one hyperthreaded core, or on both cores of a dual-core system, or on half the cores of a quad-core system.)

Was the system running both TF and P-1 when you took the snapshot in post #6?

- - -

your negativity on this forum has definitely increased

Well, gosh, I'm sorry I replied to your opening statement with "No, it takes the operating system to do that." What should I have replied, instead, that wouldn't have been negative but would still have pointed out that your assumption was incorrect? Or am I supposed to agree with statements I know to be mistakes, in order not to be "negative"?

If you think my deductions are fallacious, why don't you present evidence that demonstrates their fallacy instead of merely posting an insult?

[cheesehead]

Originally Posted by cheesehead

only half of your cores are specified to have Prime95 assignments running on them, which is why your overall system CPU usage is only about 50% even though the P-1 thread uses almost 100% of the core it's running on.

Make that:

only half of your cores are specified to have Prime95 assignments running on them, which is why P-1 uses only about 50% of your overall system CPU usage, even though the P-1 thread uses almost 100% of the core it's running on.

[cheesehead]

Let's try something else.

dominicanpapi82,

Do you realize that you've never yet told us in this thread that you've ever seen prime95 use more than 50% of the CPU?

Have you, in fact, ever seen prime95 use more than 50% of the CPU on your system?

If prime.exe does sometimes have a CPU number higher than 50%, what type of assignment(s) is it processing at those times?

Can you show us a screenshot where prime95.exe has a number higher than 50%?

[starrynte]

If I understand correctly you have 1 worker on a dual core machine, you can set multithreading to 2 to add a helper thread, if that's what you mean.

[S485122]

I was wrong : P-1 factoring is multithreaded (except during the two GCD phase, but they take about 0,2 % of the time.) Only TF would still be monothreaded. On the other hand assigning four threads to one P-1 test on a quad-core machine leaves about 30 % of the processing power unexploited : see post 94 of the thread P-1 factoring anyone that may contain answers to your interrogations.

Originally Posted by dominicanpapi82

WorkerThreads=2
ThreadsPerTest=1

Looking at the last data you provide, my theory of one worker with two threads leaving one core idle while doing single threaded tests is wrong. So far, based on the evidence you provided, I must agree with Richard, that you did not provide enough data.

What is you processor ?
When you look at the Prime95 window, are both worker threads active ? You can copy and paste the content of the individual worker windows using the edit menu of Prime95, and edit them to obfuscate all reference to exponents. That way you can post the relevant content here.
Is is possible that you have two assigments both requiring HighMem and no other work queued up for the thread that is now inactive ? You can post the content of your worktodo.txt file after obfuscating the exponents.

Before you give enough data, it is difficult to answer.

Jacob

[cheesehead]

dominicanpapi82,

I'm sorry that my statement, "... so from our points of view it seems reasonable to think that might not be the only mistaken assumption you're making", was so upsetting.

(I think that's what you meant by "your use of a very weak deductive fallacy based on something that is inconsequential to the purpose of the post". If not, please correct me.)

Writing that you had possibly made a mistaken assumption was never intended as any "accusation", or insult, or demeaning remark by me. To me, making assumptions, and occasionally being mistaken in doing so, is just part of the human condition. Mistaken assumptions are not sins; they're just ... mistakes.

I learned at an early age that everyone makes mistaken assumptions in some way or another. I also learned that most people rarely question their assumptions as often as I did. Later in life, when I started working as a computer programmer, I found that sometimes I found the answer to a problem that other, more-experienced programmers overlooked because they had been mistaken about one or more assumptions they used when trying to solve the problem.

So I began incorporating, as simply a standard step in problem-solving, the conscious questioning of assumptions that I or someone else might be making. That's why I wrote what I did; to me, it was only a standard problem-resolving step (the problem there being that I couldn't figure out why you were so sure all the rest of us were on the wrong track).

You are, and have always been, free to point out what you think anyone else is mistaken of assuming, without that necessarily being considered an insult by the other person ... and indeed that is what you have done by such statements as "I think you misunderstood. I'm not saying there is a big load on my computer taking up processor power from prime95." I took that as a simple suggestion of something I might have been mistakenly assuming. (In fact, I hadn't been assuming that you were saying that; perhaps I should've explicitly said so.)

Later, you wrote

I think you all are looking for a solution to a problem without understanding what I'm saying.

I'm not saying it's a hardware or windows issue. It's not a page file issue, my processing power isn't being taken up by another program, and (if it comes up) I'm not throttling my system. It's not anything like that. Prime95 is running as fast as it's able to, and it's still leaving unused cycles.

Again, I took that as a suggestion that I (and others) might be making some incorrect assumption in my (our) interpretation of what you had posted so far. So I replied at length to try to explain why those possibilities did not seem likely to me.

Our responses to your posts have been genuine attempts to help. We need more information to figure out the "puzzle" we see about what you've posted.

Perhaps, when this is all resolved, it will be clear that I and others were mistaken and that you had been correct all along. But right now I (and, I think, others) don't yet understand what our mistake is, so we need your help in illuminating the situation from your side, so that we can understand our mistake and then make progress after correcting our mistake. Conversely, if in fact it turns out that you have also (or instead) made some mistaken assumption, your provision of more data (that you have, but we don't) may help us determine exactly where the barrier to understanding lies.

[lfm]

Originally Posted by dominicanpapi82

Prime95 gives you the option to work on just one number because, well, you might want to work on just one number. I want to do work on just one number. Not that I need justification because many other people also want to work on just one number, but I want to work on just one number because I am working on a 100M digit mersenne that takes years to finish.

If it's true that P-1 testing can't take full advantage of multiple cores, then given that some multicore computers will be set up to work on just one number, it will definitely be an improvement in throughput (by weeks for 100M digit mersennes) if we are able to simultaneously P-1 test and trial factor the same number. I don't mean with separate code, or some slick engineering to try to save steps if that is at all possible. I mean, just do both on the same number simultaneously just like you could do P-1 testing on one mersenne and trial factoring on another simultaneously. The average PC would save time processing a single number if it simultaneously does P-1 factoring and trial factoring.

You are right, prime95 cannot use multiple cores for p-1 factoring of a single number. It only uses multiple cores on a single number for LL testing (first checks or double checks). It is not a bug, it is just what has been implemented so far. You might call it a "known problem" but most people don't consider it a problem.

Yes, it might be possible to notice this is happening and find something else for your idle core to do but it does not seem to be a high priority just now. The 100 million digit stuff you are doing is a bit far out on the radar for now. Maybe when the bulk of the testing gets out there it will be more significant.

You need to realize you are kinda out on the fringe of the project (for now at least) and development efforts have to be triaged since there is a lot of things to do and not all of them can be done at once. We still appreciate your contribution and thanks for pointing out this possible improvement. Just have patience with us while we take care of more pressing issues.

[axn]

Originally Posted by lfm

You are right, prime95 cannot use multiple cores for p-1 factoring of a single number.

Yes, it can.

[lfm]

Originally Posted by axn

Yes, it can.

Excuse me but if you are right I can't find any documentation supporting your assertion. All I find is from whatsnew.txt for Ver 25.5

5) Supports using multiple logical or physical CPUs on a single LL test.
Except for some hyperthreaded CPUs and only on some FFT sizes, this is
not recommended as you will get more throughput by giving each CPU
its own number to test.

[axn]

Originally Posted by lfm

Excuse me but if you are right I can't find any documentation supporting your assertion.

Hmmm... Perhaps George should update the documentation.

Nonetheless, it is what it is. P-1 supports multiple CPUs. Try it.

EDIT:- Also see post #17