To Hyper Thread or not?

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ChrisS
Posts: 43
Joined: Tue Apr 10, 2018 5:46 pm

To Hyper Thread or not?

Post by ChrisS »

Sorry to bother you all again!

I have just acquired a PC with an Intel Xeon X5660 Hex core processor, My first ever Hex core after a decade of Quads! It can use Hyper threading for 12 cores. Would it perform better at FAH with or without HT? Some say yes, some say no, it will starve the GPU of CPU support.
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foldy
Posts: 2061
Joined: Sat Dec 01, 2012 3:43 pm
Hardware configuration: Folding@Home Client 7.6.13 (1 GPU slots)
Windows 7 64bit
Intel Core i5 2500k@4Ghz
Nvidia gtx 1080ti driver 441

Re: To Hyper Thread or not?

Post by foldy »

I would recommend enabling it because these threads can help performance. Just keep one thread for the OS and one thread for each GPU. So if you have one GPU and 12 threads then I would run the CPU slot with 10 threads.
ChrisS
Posts: 43
Joined: Tue Apr 10, 2018 5:46 pm

Re: To Hyper Thread or not?

Post by ChrisS »

Thanks for the reply. But as a newbie here I don't know how to configure a CPU slot to only run so many threads. Any help there would be appreciated.
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JimboPalmer
Posts: 2573
Joined: Mon Feb 16, 2009 4:12 am
Location: Greenwood MS USA

Re: To Hyper Thread or not?

Post by JimboPalmer »

Choose the Advanced Control then click Configure, then choose Slots There should be a cpu slot, highlight it and choose Edit you will get a screen with CPUs having a radio button already chosen. Very likely it has -1 selected. -1 implys the program will choose the number, which is often the best choice. but you can override this to 10 (or some other number) if you want, then Save

There is some difficulties with primes larger than 5 and multiples of primes larger than 5. So 11 is a poor choice for CPUs, but 9 is fine.
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bruce
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Re: To Hyper Thread or not?

Post by bruce »

HT is normally enabled by your OS and FAH's -1 setting will choose the maximum workable setting when the Power slider is set to Full. (V7.4.4 isn't as accurate as the newer beta version.) Performance can be reduced if you reduce that setting as JimboPalmer has suggested. Lower numbers will also produce less heat, but that's really the only reason you might want to do that.

There really aren't any good reasons to tell your OS to disable HT.
ChrisS
Posts: 43
Joined: Tue Apr 10, 2018 5:46 pm

Re: To Hyper Thread or not?

Post by ChrisS »

Many thanks for all your help.
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