AffinityMask is the highest searched subject in my blog. There are many recommended values over the Internet and I’ve tried and explored many of the suggestions (see my various Posts here) for both my FSX and P3D systems.
Since early last year, I’ve been using AffinityMask=256 in my P3D setup.
I know the Binary of 255 equals to 11111111, which represents the using of all 8 cores on a Quad-core 8-Thread CPU when it is assigned for the AffinityMask.
And the Binary value of 256 equals to 0000000100000000. Well…I am not sure how many and which cores are actually used from my i7-4770K CPU under such circumstance.
However, the result is quite promising on my system. It worked similarly well on my other PC with lower hardware spec as well.
How did I find the value in the first place? It was a typo! No kidding.
The trick, unfortunately, seems to work nicely with P3D only, from v2.2 to v3.1.
Worth a try and let me know whether it works on your system.
Your mileage may vary, however.
FSX TIMES 
Hi Tom
will this work for fsx, and if not what AffinityMask value does work for fsx
thank you
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Hi Jim,
As mentioned in the post, the 256 value doesn’t work well in FSX on my system. But you could still try it to see how it works.
I am using 84 in FSX. 20 is also good when I disconnect the Saitek FIPs.
Tom
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I wonder if Dovetail did anything with FSX SE in the way of core utilization that makes the need for AffinityMask obsolete? Anyone heard anything for or against?
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Any suggestion hoe to use it with an 2500k ?
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Add the following to your Prepar3D.cfg
[JOBSCHEDULER]
AffinityMask=256
Tom
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Everything depends on a system and sim software you run.
In my case the best choice was to set this value to 254.
Of course I did tweaked many entries in my cfg but with 254 everything works best.
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Exactly. Results vary from computer to computer.
Tom
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