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Old 2020-06-19, 23:32   #45
ewmayer
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Quote:
Originally Posted by garo View Post
3) Is there a good - free - CPU temp sensor for the Mac?
I use the freeware smcFanControl app on my 10-y.o. Mac Classic. (The chassisis vintage 2010, but nothing in there has anywhere near 10 yrs usage). This is frozen at old-but-pre-iOS-crapification OS X 10.6.8. I hope said app is still available for your OS version. Running heavy both-cores-of-Core2Duo loads (which I only do for short timing tests and such) that shows temps in the 90-100C range.

What timings are you getting @3M FFT, at your throttle settings?
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Old 2020-06-20, 12:48   #46
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Quote:
Originally Posted by garo View Post
2) I assume I should turn HT off? I ran benchies and for 3M FFTs I found that 1 worker without HT gave the best throughput. OTOH given that I am running with a throttle parameter I'm not looking to maximize throughput, just the best work/energy set up.
On my newest laptop (which is based on a Intel Core i9-9880H), I've entered the BIOS and set Turbo Mode to off. On one side, this "slowed down" a bit its overall responsiveness (especially running multi-minute-long scripts), however my temps went down from 85+C to a more reasonable 60-70C, without need to fiddle inside P95's parameters.

YMMV, I'd suggest giving it a try, and decide upon results.
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Old 2020-06-21, 13:34   #47
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https://courses.edx.org/courses/cour...1T2020/course/
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Old 2020-06-21, 23:01   #48
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@Ernst: Thanks I got it via brew. Let's see how it goes.You are right though that you cannot run both cores at full blast for too long.

@ric: I have the same CPU. That's a good idea. I may try that. Using Throttle=25 currently works as the fans never go on full speed.

The iterations times being reported for the 3M FFT are more or less unchanged at 7ms for each worker (2x). But actual time for 10k iterations it about 4x as long.

I'm going to experiment with a few different combinations:
1) Throttle settings
2) Instruct Prime95 workers to use 1 or 2 cores each.
3) Turn off HT.
4) Turn off turbo - probably my least favourite option as the laptop is used for realTM work such as writing code.
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Old 2020-06-22, 08:54   #49
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Quote:
Originally Posted by garo View Post
...
I'm going to experiment with a few different combinations:
1) Throttle settings
2) Instruct Prime95 workers to use 1 or 2 cores each.
3) Turn off HT.
4) Turn off turbo - probably my least favourite option as the laptop is used for realTM work such as writing code.
I'd say that Turbo is the least useful option (it amounts to overclocking and thus heating up).

Throttling, means the software starts and stops all the time, I would not recommended it.

I would not turn off HT which can help if you have to do "real" work. Anyway writing (code or whatever) is not a task that uses much of the hardware processor, it tends to be hard on the software (biological) processor though.

In Windows and Linux it is possible to limit the speed of the processor. It is definitely the option I would recommend unless you can have access to the BIOS, and that there is an option to limit the power draw (such options adapts the speed in order not to exceed the value set.)

Jacob
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Old 2020-06-22, 22:27   #50
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@Ernst: Got a newer app called macs fan control. smcFanControl hasn't been updated for four years and for some reason had the fan RPMs all wrong for me. The new app seems to be running fine and has more detailed info including temps of individual control.

@S485122: You are correct. I will try disabling turbo and see how it goes. I believe with a faster fan speed and limiting CPU speed to 2.3GHz rather than the 3.5 it turbos to, I should get a better handle on the temps.

Disagree about HT though. With 8 cores I doubt my workloads would suffer from lack of HT. I have turned it off so will report back on any performance impact I see.

Last fiddled with by garo on 2020-06-22 at 22:28
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