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Fluent is so slow (CPU consumption problem)

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Old   August 7, 2020, 06:56
Default Fluent is so slow (CPU consumption problem)
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I am using fluent to simulate and analyse a flow past a cylinder. My computer has 8 cores and 16 logical processors. When open fluent, I always run in parallel with 8 solver processes. However, the simulation run very slow and I don't get the speed I am expecting. The task manager always shows that 5-6% of the CPU consumed by cx2010 while each of the 7 fl_mpi2010 consume 6-7% of the CPU. I have another 2 cores laptop which shows that 25% is consumed by the cx2010 while only 2 fl_mpi2010 files consume 10% each. Whats going wrong here and how can I increase the speed of my runs?
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Old   August 7, 2020, 15:45
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Turn off Hyper-threading and use only real cores. Fluent like many other CFD codes don't like Hyper-threading.


UPD

BTW 100/16 = 6.25 % - Task manager shows percent of total CPU load. One full loaded core is 6.3% of whole CPU. If you check the total load you see 55% value which corresponds to 8 of 16 cores fluent plus some load for Windows.

Last edited by karachun; August 7, 2020 at 18:41.
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Old   August 7, 2020, 16:38
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Thanks karachun,

How can I turn off hyper-threading?
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Old   August 7, 2020, 18:41
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From BIOS, check your motherboard documentation.
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