[gridengine users] num_proc and hyperthreading

Reuti reuti at staff.uni-marburg.de
Tue Jul 19 10:34:17 UTC 2016


> Am 19.07.2016 um 10:22 schrieb Rémy Dernat <remy.d1 at gmail.com>:
> Hi,
> I have many nodes with hyperthreading enable. 
> I would like to know if modifying the complex value 'num_proc' or 'slots'

Setting slots would be the way to go.

> to the half of cores is the same thing that to disable the hyperthreading.


> If not, what is the difference ?

Limiting the slots will still allow the OS to use the additional threads. And it's still up to the OS where to put each thread.


Switching it off on a BIOS level will also change the internal operation of the pipeline in the CPU as there are no threads to handle any more. IIRC there was something about it on the Beowulf list.

-- Reuti

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