Prime95 PM Slowdown?

[Primeinator]

Hello,

I've been noticing for some time that Prime95 25.9 has been slowing down in the nighttime hours and early morning by a considerable amount. I am running two LL tests in the 45M range on a Core 2 Duo 2.0Ghz.

During the day, the LL test usually paces at about .098 to .1 seconds per iteration. However, during the night this slows to from .11 to .14 seconds per iteration. Note- nothing else is running on my computer. I figured that a night or two would could be dismissed as an anomaly, but this has been happening for weeks. Any ideas on what is wrong?

Thanks.

[cheesehead]

Originally Posted by Primeinator

During the day, the LL test usually paces at about .098 to .1 seconds per iteration. However, during the night this slows to from .11 to .14 seconds per iteration. Note- nothing else is running on my computer.

The first thing I'd do would be to question the last item. If you've already tried monitoring the system for other tasks running during the times of slowdown, and found nothing, then I'd suspect a malware infection.

[S485122]

Before thinking of malware I would think of anti-malware : antivirus programs for instance. Take MS Forefront : is a resource hog and will use more than three CPU hour in a workday for updates and "quick" scans.

Jacob

[Uncwilly]

Another known pig is defrag software. But that should only run 1 time a week.

[cheesehead]

Originally Posted by S485122

Before thinking of malware I would think of anti-malware : antivirus programs for instance. Take MS Forefront : is a resource hog and will use more than three CPU hour in a workday for updates and "quick" scans.

Originally Posted by Uncwilly

Another known pig is defrag software. But that should only run 1 time a week.

... and in either case, legitimate software would have shown up on a system monitor listing active tasks. So if there's already been a check for other tasks that came up empty, malware is the next suspect.

[Primeinator]

Sorry, I have been away for a while. Spyware was the first thing that I checked- AVG 8.5 Free declared my computer spyware and virus free.

The only thing I can think of (that is probably wrong) is that somehow my Prime95 memory settings (which are much higher at night) are affecting the LL and confusing the test somehow, even though LL's do not use that much memory. This is probably a wrong idea, but it's the only one I can think of.

[cheesehead]

Originally Posted by Primeinator

Sorry, I have been away for a while. Spyware was the first thing that I checked- AVG 8.5 Free declared my computer spyware and virus free.

That's nice, but does AVG absolutely guarantee that it will find 100% of malware? Probably not.

The only thing I can think of (that is probably wrong) is that somehow my Prime95 memory settings (which are much higher at night) are affecting the LL and confusing the test somehow, even though LL's do not use that much memory. This is probably a wrong idea,

Yes.

but it's the only one I can think of.

I've had malware infections that were completely undetected in scans by major-brand antivirus/antispyware. Cure: Wipe the software disk and reinstall Windows XP.

Because of the reliable repeatability of LL iterations, I recommend that persistent unexplained timing discrepancies such as you report should be considered suspicious, possible evidence of malware, until proven otherwise.

[garo]

It might be as simple as AVG running its daily scan in the early hours of the morning.

[Primeinator]

Originally Posted by cheesehead

That's nice, but does AVG absolutely guarantee that it will find 100% of malware? Probably not.

I've had malware infections that were completely undetected in scans by major-brand antivirus/antispyware. Cure: Wipe the software disk and reinstall Windows XP.

Because of the reliable repeatability of LL iterations, I recommend that persistent unexplained timing discrepancies such as you report should be considered suspicious, possible evidence of malware, until proven otherwise.

I have Vista, but the process would be the same. That's fairly drastic, don't you think? Is there a simpler alternative?

Originally Posted by garo

It might be as simple as AVG running its daily scan in the early hours of the morning.

No. I have modified the settings of AVG to run only once a week.

[cheesehead]

Originally Posted by Primeinator

I have Vista, but the process would be the same. That's fairly drastic, don't you think? Is there a simpler alternative?

Sure. Live with the problem.

I didn't tell you to wipe your disk and re-install. I said that was the cure in a case I had.

I'm not declaring that malware must be what's happening in your case. I'm saying that you haven't ruled it out with the measures you've reported so far.

[joblack]

You can do some performance monitoring with the normal windows tools ... I think you can find it under adminstrative tools.

Check after a day what process are stealing your processor cycles.