How to Set CPU AFFINITY without using FSX.CFG

[Paul_Smith 92]

I have found that using[JOBSCHEDULER]Affinitymask =14or any value in the FSX.CFG file does not work.

Sorry mate, that is not what the rest of us have found. I suggest that you make sure that you have not assigned an affinity to the executable through the task manager. The would override anything in fsx.cfg.

[cj-ibbotson 81]

To find your ideal AF you should Google - Binary to Decimal Convertorhttp://mistupid.com/computers/binaryconv.htmI recently did this as most people seem to only quote for 4 core cpus rather than the 6 core 980x I have.With hyperthreading switched off I want a config of 111110 so that the last core is kept free which is a AF of 62If hyper threading was enabled (12 cores) then it would be 111111111110 = 4094For 4 cores 1110 = 14, 1100 = 12Play around with the converter folks

[JSkorna 137]

In both of your examples it is the the first core (core zero) that is free. You read the cores from right to left.

[Pete_Smith 1]

I understand what you're getting at. I've seen this mentioned at Tom Tsui's website "FSX Times"

Toms blog is very interesting, I always pay a visit there each week.Pete Smith

[zachlog 18]

Hi,It's a setting in your FSX.cfg file that instructs FSX as to what CPU cores to run on.

Jim,There is no "Affinitymask" in my FSX.CFG file. Is there a specific section where it must be placed ? There is a post further up with a section called [JOBSCHEDULER] ?Thanks,Zach

[JSkorna 137]

Yes, under JOBSCHEDULER

[zachlog 18]

Yes, under JOBSCHEDULER

Jim,Thanks a lot ! I just looked for section JOBSCHEDULER and it's not in my FSX.CFG. Do you know of a source where the JOBSCHEDULER parameters are documented ? Also, can the JOBSCHEDULER section be placed anywhere in the FSX.CFG ?Zach

[Ben Cap 89]

Tweak as much as your heart's desire but honestly, use THIS tool for the best tweaks without having to fiddle around with numbers for hours on end.

[JSkorna 137]

Zach,That is just a section title so there are no values associated with that. Yes it can be placed anywhere. It is the AffinityMask= line that has the values.

[cj-ibbotson 81]

Tweak as much as your heart's desire but honestly, use THIS tool for the best tweaks without having to fiddle around with numbers for hours on end.

The ******* tool gives you the wrong AF settings. Despite telling it I had 6/12 cores and tried both options of HT on or Off it gave me a value of 56 and 1366 which resulted in about half my cpu cores being disabled. Use the converter I posted a link to and place a zero for which cores you want unused by FSX

[Jen 0]

Jim,I do not have an 'AffinityMask=' line in my fsx.cfg file. Should I add: AffinityMask=14 to the last line in my cfg file or what?jen noulet

[JSkorna 137]

Yes, and that would give you FSX running on cores 1, 2, and 3, with core 0 for your OS and utilities.

[Paul_Smith 92]

The ******* tool gives you the wrong AF settings. Despite telling it I had 6/12 cores and tried both options of HT on or Off it gave me a value of 56 and 1366 which resulted in about half my cpu cores being disabled. Use the converter I posted a link to and place a zero for which cores you want unused by FSX

What makes you think that is wrong? FSX doesn't load balance or anything sophisticated like that. It does the majority of its work on a single core. If allowed, it will do some texture loading etc using other cores, but afaik, beyond three cores shows no measurable improvement.

[Jen 0]

Thank you Jim. I'll give it a try.Regards,jen noulet

[cj-ibbotson 81]

What makes you think that is wrong? FSX doesn't load balance or anything sophisticated like that. It does the majority of its work on a single core. If allowed, it will do some texture loading etc using other cores, but afaik, beyond three cores shows no measurable improvement.

Its wrong because it's giving the wrong decimal value for the binary equivilent for the amount of cores I wish to use. In most cases the majority of people just disable Core0. It also always gave me poorer performance if I accepted the tools values.