BACKGROUND: I am very vigilant about heat levels when running BOINC Manager 7.0.25 (x86). On my iMac (2.93 GHz Intel Core 2 Duo, 4 GB 1067 MHz DDR3, NVIDIA GeForce GT 130 with CUDA installed, running Mac OS X Version 10.6.8) I use iStat Pro, a free widget, to monitor heat levels for CPU, CPU Heatsink, GPU Diode, GPU Heatsink, Northbridge and Power Supply.

PROBLEM: When I run only 1 task, the heat levels stay within the range I require. When I run 2 tasks simultaneously the heat levels increase significantly and exceed the range I require. Thus, I run 1 task and Suspend the rest. If I am not available when the 1 task completes, my iMac stays idle until I resume the next task.

POSSIBLE SOLUTION: Add a setting in Preferences for Tasks. The setting would allow for checking the number of tasks to run simultaneously, i.e., 1, 2 or 3 and so on. This way if "1" is selected the remainder of the tasks would not have to be Suspended, and the next task would run immediately after the 1st one completes.

Just a suggestion.

Thanks,

Jim Minor

Set your preferences for:
On multiprocessors, use at most X% of the processors, to 50%. Since you have a 2 core CPU, this will use only 1 core, thus 1 task at a time.

Check local preferences if the web-preferences don't do this. Local preferences override web-preferences.

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Set your preferences for:
On multiprocessors, use at most X% of the processors, to 50%. Since you have a 2 core CPU, this will use only 1 core, thus 1 task at a time.

Check local preferences if the web-preferences don't do this. Local preferences override web-preferences.

You might also look into smcFanControl to boost the fan speeds.
http://www.macupdate.com/app/mac/23049/smcfancontrol

It might help to keep the temps down. Also make certain that the vents are cleaned regularly.

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Thank you for the information. Here's what I did.

Computing Preferences: I set "On multiprocessors, use at most" I set to 1. I set "On multiprocessors, use at most" I set to 50% of the processors. And, I set "Use at most (Can be used to reduce CPU heat" I set to 75% of CPU time.

Now only 1 task runs at a time and the heat levels stay within the range I require.

Thanks again ...

Jim Minor

I also throttle my cpu time to avoid high electric consumption/heat. Is there still an advantage to optimized apps when you run your CPU throttled down?

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#resist

xclusive585: Is there still an advantage to optimized apps when you run your CPU throttled down?

I don't know if there is an advantage to optimized apps when you run your CPU throttled down. After I throttled down to what I indicated in my previous post, I did not notice any significant difference in how fast a BOINC Manager 7.0.25 task runs. My major concern was not to exceed certain heat limits for CPU, CPU Heatsink, GPU Diode, GPU Heatsink and the Power Supply.

I searched Apple and other web sites for information about heat limit ranges for my iMac but could not find the information I was looking for. Thus, I would rather be conservative when it comes to heat build up.

Also, the app to increase the fan speed requires Mac OS X Lion. I'm running Snow Leopard.

Jim Minor

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xclusive585: Is there still an advantage to optimized apps when you run your CPU throttled down?

I don't know if there is an advantage to optimized apps when you run your CPU throttled down. After I throttled down to what I indicated in my previous post, I did not notice any significant difference in how fast a BOINC Manager 7.0.25 task runs. My major concern was not to exceed certain heat limits for CPU, CPU Heatsink, GPU Diode, GPU Heatsink and the Power Supply.

I searched Apple and other web sites for information about heat limit ranges for my iMac but could not find the information I was looking for. Thus, I would rather be conservative when it comes to heat build up.

Also, the app to increase the fan speed requires Mac OS X Lion. I'm running Snow Leopard.

Jim Minor

Actually it's minimum system is 10.4 (Tiger), I have it running just fine on my iMac C2D running Snow Leopard.

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Thanks arkayn. I downloaded the app. Guess I spent to much time out in the sun today.

Jim Minor