Can't get 2 CPUs to process

[Nicola]

Hi,

I'm a new folder, with one WU finished. I can't get both my CPUs to process.

Intel C2D 2.1GHz
Memory 3GHz
Windows XP SP3
F@H Version 7.3.6
PRCG 8702 (7,59,28)

I'm folding on a laptop. Default settings caused overheating. I turned the percent CPU usage from 100% to 90% which was reasonably cool (fan stays on low). Then, I tried alternatively to switch to one CPU at 100% power. This worked, but I think it may be slower than 2 CPUs at 90%. The problem is, try as I might, I can't switch back to 2. I have tried setting CPUs at both -1 and 2, but in both cases, if I look in task manager FahCore_a4.exe is never running at more than 50%.

Here is my log of an attempt to set to -1

19:11:05: <!-- Folding Slots -->
19:11:05: <slot id='0' type='CPU'>
19:11:05: <cpus v='-1'/>
19:11:05: </slot>
19:11:05:</config>

If you need log contents from when the error occurred, I will try to provide that, but it would be hard to remember exactly. I don't want to cut and paste my whole log file here as it's long, and I'd have to go through it and remove my name each time it occurs.

I'm a beginner at this, and using a minimal system I know, but I'd still like to contribute as best I can.

Nicola



If you need more information from my log, for example from the time when the

[bruce]

Except in unusual cases, when the slider is set to "FULL" the setting <cpus v='-1'/> will cause the client to allocate all of your CPUs on a single WU. (Also known as SMP and in your case, it's the same as CPU:2.)

You may be a beginner, but you've asked a really tough question. It's pretty difficult to manage the usage on dual-core systems because the percent CPU usage setting is essentially ignored by those projects. The slider does it by forcing a choice between one CPU and two with no other choices other than off.

Alternating between two projects isn't going to work either, because temperature stabilizes quickly to whatever is running. You're probably stuck with running CPU:1 if 2 is too hot.

[Nicola]

My computer was not overheating when running 2 CPUs at 90%. The problem is that I can't figure out which settings to use to make the software run that way again. It was running that way before. Then I changed it to run on 1 CPU, and I can't seem to change it back. Setting the slider to Full makes no difference--I'm still running only on one. (with cpu set to -1)

For me the Percent CPU usage setting does work. Whatever I set it to, FahCore_a4.exe runs at half that number (because I'm somehow stuck on using only one CPU, even with the slider at full.)

I'm beginning to think my software is not behaving normally!

Nicola

[Napoleon]

I'm not absolutely sure about this, but I have a hunch that changing CPU:n back and forth in the middle of a WU doesn't (always) work as expected - you end up finishing the currently running WU the way you started it, no matter what you try. The next WU should be OK, though.

[Jesse_V]

I'm not absolutely sure about this, but I have a hunch that changing CPU:n back and forth in the middle of a WU doesn't (always) work as expected - you end up finishing the currently running WU the way you started it, no matter what you try. The next WU should be OK, though.

Yes. The next work unit (the small packets of work a computer is given to do) should have the updated setting. Some FahCores and work units support the mid-WU change, others don't. One could look in the log for evidence of whether the setting was applied or not.

[bruce]

For me the Percent CPU usage setting does work. Whatever I set it to, FahCore_a4.exe runs at half that number (because I'm somehow stuck on using only one CPU, even with the slider at full.)

I'm beginning to think my software is not behaving normally!

Actually, that's normal. What I think happens is that CPU:2 starts two threads and the %CPU setting reduces the setting of one thread. The other one runs at 100%, so setting it to. say 80%, will result in 80%+100% or and average of 90%. After you change that setting, the WU may automatically pause and resume work or you may have to manually pause it and then click FOLD again to get it to accept the new settings.

For somebody with, say 8 cores, they can set it to say 50% and it'll run at 50% + 100% + 100% + 100% + 100% + 100% + 100% + 100% and they'll see an average of 94% and they'll say it isn't working because they're expecting 50% + 50% + 50% + 50% + 50% + 50% + 50% + 50% for an average of 50%. With only two cores, you're welcome to use it if it gives you what you want.

[P5-133XL]

Often, if you start a WU using a single CPU thread/core it will stay that way, even if you tell the client to use two threads, till the next WU is started. That's because you likely started a true uniprocessor WU. So, moving back and forth between a single thread and multiple threads doesn't work so well.

I would suggest that you set the client to use two threads and run in full-mode. Then let the current WU finish and the next WU fetched should be a multi-CPU WU. If you need to adjust the CPU slider to make sure that your laptop doesn't overheat then that's fine but do not expect it to work the way think it ought to because it works more like what Bruce said.

In the end, the best solution is to fix the cooling on your laptop so it can run at 100% without overheating and without having to fiddle with software settings. It may need some canned air to clean the cooling system of debrie, a new application of thermal grease, or you may need to make sure the exhaust vents are not hindered. Whatever it takes...

[Nicola]

Thank you all for the helpful replies. I appreciate your expertise. I've set my CPUs to 2, so I'll see if that takes effect when I get my next WU at the end of the week. In the meantime, I am able to finish WUs before the assigned timeout, so this is all just a question of efficiency. And bonus points!

I also appreciate the tips about improving cooling.

I may have some follow-up questions, but for now, I have action items. Thanks again,

Nicola

[codysluder]

It's not clear to me exactly what you want from F@H. Judging from the title, maybe it's your desire to have on CPU idle and one folding. The default is to have both cpus working to speed up a single WU but that has been overheating your machine. Having each cpu working on a different WU won't improve the heating situation except if the %CPU slider works. Having some percentage of each one contributing to the processing of a single WU produces more science than asking FAH to devote half that amount of processing to each of two WUs.

[TheWolf]

x

[P5-133XL]

The %CPU usage setting in v6 does the same as the CPU slider in v7. The client.cfg is from v7.

[TheWolf]

x

[codysluder]

Don't waste your time installing V6. Bruce has already explained how the fahcore's do or do not work based on the value passed from either the V7 or the V6 client five posts above. The fahcores invoked by the v6 client are also invoked by the v7 client and they share the same limitations. It's the fahcore that either uses a full cpu or a fraction of the cpu, The client just tells it what you want to do.

[TheWolf]

x

[JiniHammerer]

Its does Wolf. under configure , the advanced tab you can define how much CPU max you want to use.