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How to increase core usage/performance?

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Old   October 28, 2021, 04:46
Default How to increase core usage/performance?
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Hi all, I am totally new to fluent and am running through Cornell uni's beginner free course. During the videos, the presenter runs some simulations that take mere seconds on his computer for thousands of iterations. While I am only using an i7 7700hq cpu (gtx 1060 too if it matters), my pc took quite a few minutes just to do one iteration! I feel that something is wrong here, but I don't know how to change anything.

On the fluent launcher I selected double precision as the presenter said to, and can't figure out where to change other options. My cpu is quad core with 8 threads and I have no idea how to tell if fluent is taking the full use of my cpu.

Any ideas? Thanks!

Edit: On a whim I tried setting 'number of processes' to 3 and it seems to do the trick. For a quad-core laptop, is it safe to put 4?

Last edited by cons013; October 28, 2021 at 04:52. Reason: figured it out sort of
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Old   October 28, 2021, 06:17
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Ye you can put 4, because most probably your processor has hyperthreadening. Infact, you can check it in the windows devicd manager, you should see 8 processors even though there are only 4 physical ones. Check the temperatures while running though
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Old   October 28, 2021, 06:22
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Thankyou!!
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Old   October 29, 2021, 00:12
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as far as I know it is recommended to run fluent with number of nodes equal or less to number of physical cores you have (4 in your case). some times you may reserve 1 core for other programs.

its not possible to have such a big difference in performance, which you've mentioned. There must be a difference in cases.
running case on 4 cores instead of 1 will almost never increase computational speed 4 times.
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Old   October 29, 2021, 00:27
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I don't really know what was wrong. Fluent was being weird in general. First there was the painfully slow performance, then fluent itself wouldn't close when I clicked exit, I don't know. It seems to be working fine now.
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Old   November 6, 2021, 01:54
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Open up Windows Task Manager and observe how the CPU, Memory (RAM) and HDD parameters behave when Fluent is running. I donít think Fluent solver need to access your GTX 1060 graphics for the computational process, unless you tick the option at startup, but I suspect that itís not possible with a 1060 card.

It could be a number of things. Perhaps not enough RAM and needs to constantly write to a slow HDD.
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