Murine Hesitation and Prime95
 

My main PC is an i5-4680k running Win 10 and Prime95.I'm actually in the process of building some dedicated hardware for prime hunting, but I would also like to run it on my main PC.

When running Prime95, my machine is certainly usable, but it feels like my mouse occasionally stutters or freezes. Is that normal? I've run BOINC projects before without issue (as long as I didn't use my GPU while using the machine).

On a normal healthy system, should you be able to run Prime95 full throttle and see no difference? I left priority at 1, and have tried throttling in the config file, as well as trying with only 3 out of 4 cores dedicated, but the issue persists. I'm just using the stock CPU cooler that came with the i5, but I haven't overclocked. Thoughts?

[QUOTE=Fred;424571]My main PC is an i5-4680k running Win 10 and Prime95.I'm actually in the process of building some dedicated hardware for prime hunting, but I would also like to run it on my main PC.

When running Prime95, my machine is certainly usable, but it feels like my mouse occasionally stutters or freezes. Is that normal? I've run BOINC projects before without issue (as long as I didn't use my GPU while using the machine).

On a normal healthy system, should you be able to run Prime95 full throttle and see no difference? I left priority at 1, and have tried throttling in the config file, as well as trying with only 3 out of 4 cores dedicated, but the issue persists. I'm just using the stock CPU cooler that came with the i5, but I haven't overclocked. Thoughts?[/QUOTE]

I've never experienced any kind of mouse stuttering like that when Prime95 is running. Just to make sure, you might try stopping Prime95 the next time you're doing some interactive work on that system... just do your normal stuff and see if the issue goes away, or maybe it still happens.

If you didn't have any problems at all with Prime95 stopped, go ahead and start Prime95 up again and do your normal stuff and see the issue re-appears.

[QUOTE=Madpoo;424590]I've never experienced any kind of mouse stuttering like that when Prime95 is running. Just to make sure, you might try stopping Prime95 the next time you're doing some interactive work on that system... just do your normal stuff and see if the issue goes away, or maybe it still happens.

If you didn't have any problems at all with Prime95 stopped, go ahead and start Prime95 up again and do your normal stuff and see the issue re-appears.[/QUOTE]

Yes, it's my main system I use all day, so I've had plenty of time to experiment. The problem definitely starts and stops with Prime95. I've had the system a number of years, and running Prime95 is the only thing that causes it. As soon as I stop Prime95 from crunching data, the issue goes away.

[QUOTE=Fred;424596]As soon as I stop Prime95 from crunching data, the issue goes away.[/QUOTE]

Hmmm... Are you running LLs, DCs, or P-1's? How many tests are you running? How many cores are you running?

From my experience only large memory usage tests (e.g. P-1, ECM) cause problems such as you describe, unless there's a deep issue with your kit which you should try to figure out.

Is there any chance you could share with us your box's specs, and the work it is doing? Importantly, please don't post here your worktodo.txt file. Just post the specs and the candidates you're working.

[QUOTE=chalsall;424599]Hmmm... Are you running LLs, DCs, or P-1's? How many tests are you running? How many cores are you running?

From my experience only large memory usage tests (e.g. P-1, ECM) cause problems such as you describe, unless there's a deep issue with your kit which you should try to figure out.

Is there any chance you could share with us your box's specs, and the work it is doing? Importantly, please don't post here your worktodo.txt file. Just post the specs and the candidates you're working.[/QUOTE]

Good idea for more info.

If it's doing a test that uses a lot of memory, could be the rest of the apps are just memory starved? If you're using the pagefile, that would definitely cause wonkiness when doing some things that end up swapping to disk.

Also, core 0 would be the interrupt handler for the system. I think mouse activity is interrupt driven (or am I thinking WAY back to a time before USB input devices?)

You might try stopping just the worker running on core 0 and see if that alone helps? Or just check and see what your overall memory % used is like, in case it's close to maxing out physical RAM?

Prime95 doing LL tests doesn't use a lot of memory. As chalsall points out, P-1 and ECM would be the memory hogs, if that were the case.

[QUOTE=Madpoo;424606]You might try stopping just the worker running on core 0 and see if that alone helps?[/QUOTE]

Prime95 never works at trust level 0. That's the OS' domain....

Try running HWmonitor (or a similar program) to monitor CPU temps. Perhaps you have thermal throttling due to a dusty or poorly attached heatsink.

[QUOTE=chalsall;424608]Prime95 never works at trust level 0. That's the OS' domain....[/QUOTE]

Not trust zero, core zero. :) First core is generally going to handle interrupts (dual socket systems would have some PCI slots going to one CPU or the other, which handles the interrupts for those lanes... hopefully I'm not mangling the terminology too bad).

The only time I've experienced mouse movement problems is when my HDD was failing and required more tries to read the sector(s) correctly. It may be that P95 is using more memory and causing all apps to save/load more stuff from the pagefile (as another poster already mentioned) and thus exposing the underlying problem of HDD errors.

Thanks all for your thoughts and ideas. I think I have the problem resolved, although it's still a little confusing. Turns out I think it was an issue with my mouse. I have a logitech wireless M510 mouse. When I switch to a different wireless mouse (had a logitech M310 handy), the problem goes away. Very strange, but easy fix.

You would think it's something just up with that mouse (I ruled out batteries, etc), but the original mouse behaved perfectly as long as Prime95 wasn't crunching away. Strange, but glad it's resolved.

[QUOTE=Fred;424706]Thanks all for your thoughts and ideas. I think I have the problem resolved, although it's still a little confusing. Turns out I think it was an issue with my mouse. I have a logitech wireless M510 mouse. When I switch to a different wireless mouse (had a logitech M310 handy), the problem goes away. Very strange, but easy fix.

You would think it's something just up with that mouse (I ruled out batteries, etc), but the original mouse behaved perfectly as long as Prime95 wasn't crunching away. Strange, but glad it's resolved.[/QUOTE]

Some Logitech mice have a report rate setting, in addition to the more common DPI/speed settings. Perhaps if that is too high, Prime95 and the mouse drivers end up fighting for the CPU, causing stuttering.

You could try playing with your mouse settings, to see if you can make the problem go away.

[QUOTE=Fred;424706]Thanks all for your thoughts and ideas. I think I have the problem resolved, although it's still a little confusing. Turns out I think it was an issue with my mouse. I have a logitech wireless M510 mouse. When I switch to a different wireless mouse (had a logitech M310 handy), the problem goes away. Very strange, but easy fix.

You would think it's something just up with that mouse (I ruled out batteries, etc), but the original mouse behaved perfectly as long as Prime95 wasn't crunching away. Strange, but glad it's resolved.[/QUOTE]

I have an old crappy pair of Logitech webcams and when I have them both plugged in and streaming basic 640x480 video, sure enough my CPU usage spikes horribly.

They're USB and the drivers may or may not play a part in that, or just that they're both flooding USB with a lot of traffic or who knows what.

I can only imagine what would happen if I were running Prime95 at the same time because if it's interrupt driven, there will be some mild system thrashing going on.

With that said, I'd speculate it could be similar to your mouse problem with the M510, but the M310 is better.

Like Mini-Geek says, maybe there are some settings for the mouse about the rate... if you move the mouse an inch and it generates a ton of activity because the dpi is cranked way high (for gaming purposes or who knows what), I could see that doing strange things if the CPU is otherwise highly active.

One way an application could affect the interrupt latency is if it pushes the interrupt service code out of the cache(s) and increases the time to load the service code from RAM. Another possible effect (in the reverse direction which would improve response time) is that keeping the CPU active, and out high of C-states, will make everything happen faster. I think in both of these cases the difference is micro-seconds and wouldn't be noticeable to the user. So what else could it be?

[QUOTE=retina;424721]One way an application could affect the interrupt latency is if it pushes the interrupt service code out of the cache(s) and increases the time to load the service code from RAM. Another possible effect (in the reverse direction which would improve response time) is that keeping the CPU active, and out high of C-states, will make everything happen faster. I think in both of these cases the difference is micro-seconds and wouldn't be noticeable to the user. So what else could it be?[/QUOTE]

Perhaps a driver that also runs at idle priority, so it'll be fighting for scraps of time with a CPU heavy app? Doesn't seem likely though.

It really does not seem that this thread is an appropriate target for Title Morphing. A new user is involved, and it is a technical issue.

[QUOTE=Fred;424706]Thanks all for your thoughts and ideas. I think I have the problem resolved, although it's still a little confusing. Turns out I think it was an issue with my mouse. I have a logitech wireless M510 mouse. When I switch to a different wireless mouse (had a logitech M310 handy), the problem goes away. Very strange, but easy fix.

You would think it's something just up with that mouse (I ruled out batteries, etc), but the original mouse behaved perfectly as long as Prime95 wasn't crunching away. Strange, but glad it's resolved.[/QUOTE]

I switched from a M310 to a M510 and have never had an issue, so it could well be a faulty M510.
I am using:-
Windows 7
Setpoint Control Centre version 6.67.83
Driver version 5.90.41

I suppose another possibility is that the driver is not fully compatible with Windows 10.

Prime95 stresses a pc more than almost anything else. It is fairly normal to have a slightly sluggish pc when it is running. This was more of an issue on single core pcs. It can also effect pcs with more cores. My old Athlon 64 3800 was terrible. Memory bandwidth starved pcs can be bad ones. Memory bandwidth would be an issue with that cpu although we haven't had loads of people complain about it. What speed is your memory?

[QUOTE=henryzz;424840]Prime95 stresses a pc more than almost anything else. It is fairly normal to have a slightly sluggish pc when it is running. This was more of an issue on single core pcs. It can also effect pcs with more cores. My old Athlon 64 3800 was terrible. Memory bandwidth starved pcs can be bad ones. Memory bandwidth would be an issue with that cpu although we haven't had loads of people complain about it. What speed is your memory?[/QUOTE]

DDR3-1600, I'm sure that's not helping anything.

Honestly at this point thought, the M310 is working perfect with Prime95 happy chugging away, so I just assume not troubleshoot any further. At some point, the ROI of time vs. a $20 mouse just aint there ;)

[QUOTE=Fred;424855]DDR3-1600, I'm sure that's not helping anything.

Honestly at this point thought, the M310 is working perfect with Prime95 happy chugging away, so I just assume not troubleshoot any further. At some point, the ROI of time vs. a $20 mouse just aint there ;)[/QUOTE]

I've run Prime95 on current systems with DDR2-800 speeds and while it's nowhere near what I can get out of other systems, I haven't seen any other performance issues in the process.

I wouldn't make a blanket statement that you'll never have an issue when Prime95 is running, but it's more likely that there's just some other hardware, driver, app, whatever that simply doesn't play nice with others. Maybe a particular driver that expects there will always be ample CPU for it to do it's magic, or a PSU that works great as long as your not stressing the system and reaching peak TDP for CPU/memory, or a CPU that does fine in lower c-states but chokes when pushed to the max.

One thing is for sure... if your system is marginal in any large or small way, there's a good chance Prime95 will reveal that. Which makes it an awesome stress tester.