Affinity mask?

Roger

Roger

Senior Administrator
Anyone know what job scheduler/ affinity mask I should use in the FsX.cfg for an i5 4670k cpu?

Thanks in advance,

Roger.
 
With 14, you will have the last three cores using FSX, which is, in my testing with an i7, the best solution (running on the three first (affinity = 7) gives more stutters). If you've 8 cores (HT enabled), affinity=63 will gives you the last 6 cores for FSX.
 
Interesting, I always thought 15 using all 4 cores (apparently not needed, read someplace FSX default uses all cores) was the way to go.
I tried 14 and restarted and seemed slightly smoother around La Guardia, but then again might have been because of the restart.
Currently using GameBooster to shut down everything else unless they caution not to.
Anyone have any thoughts on the benefits of not using all cores when default is all?
 
It's 'affinity mask' and it's a line in your fsx.cfg to force fsx to use the multiple cores of your processor (if your processor is a multi core, of course). The number indicates a binary number, so 14 ask fsx to run on three cores, 15 on 4, etc... the 1 and 0 in the binary number indicating which of the cores are used (it seems that it's a little bit more complicated, the core 0 is used by fsx with affinity mask on 14, but only for very specific tasks)

With 14, the three (1, 2, 3) last cores are used, and it's often mentionned as the best solution, because core 0 is used by the system and by the other pograms you are using (in my particular case, I use also the task manager to force the other programs to run on core 0, especially the TIR program). I've made lots of testing in last weeks, because I'm overclocking my processor, and had great differencies of temperature on each core. So, I test the affinity mask on 7 (three first cores), 15 ( all cores) and the result was really different than with 14. Not a problem of FPS, but stutters. So I confirm that 14 is the best solution... but my computer is not the same as yours, so the best is trying by yourself. The good news is that the difference is really noticeable, especially if you test without and with the affinity mask...

There's a place in the fsx.cfg to put that line, it's the chapter 'jobscheduler' You can take a look here : http://fsxtimes.wordpress.com/2010/08/18/affinitymask/

Sorry for my poor english.
 
I run pretty much tweak free, but out of curiosity I decided to try this out (4 cores) and saw no difference in smoothness or FPS, but thanks for the info though, at least i know what it is supposed to help with now, LOL.
 
MCDesigns said:
I run pretty much tweak free, but out of curiosity I decided to try this out (4 cores) and saw no difference in smoothness or FPS, but thanks for the info though, at least i know what it is supposed to help with now, LOL.
Click to expand...

Affinity Mask is one of the few tweaks that actually works and it poses no threat to your hardware or software as was asked earlier
I have an I5 with 4 cores and have Affinity Mask = 14

compared to running the sim without it? big difference...

not as in more FPS - just smoother fluidity

for best results you will use this tweak in concert with the others that work well as in http://kostasfsworld.wordpress.com/fsx-software-and-hardware-guide/
 
I have mine setup over 7 (out of 8 cores) using the last to first option and the fluidity is much better in FSX.. Tried it in P3D as well and noticed a significant difference. I was a little worried about overheating the CPU, but it doesn't seem to go above 53 degrees with my AMD rig.
 
I'm not an hardware technician, so what I say is only intuitive, but I think the tweak can't harm your processor. It's easy to see the effect with the task manager or any program that show the activity of each core. With the tweak, core 0 is and stay at 100% all the time. The three others are very quiet, if (like me) you run only fsx-related programs (in my case : track IR and AS2012 or Opus FSX). With the tweak, all the cores are working, core 2 and 3 are at 100% most of the time.

My logic is that it's better to make a good repartition of the workload on each core.

You can use a program like CPU temps and look the diffencies with or without the tweaks, while running FSX. That's very instructive.

IMHO, changing the affinity mask is not really a tweak, it's the way to tell the old fsx that the processor are now multicores, and that's a big change since 2006...
 
GDavis,

Do you have the AMD 8150? What AffinityMask are you using? after a lot of reading, I was under the impression that AffinityMask=253 is the setting for 8 cores, but I saw 63 in a post here.
 
I have an AMD FX 8350, I set mine to just use 7 out of the 8 cores just to see what would happen.. My thinking was to have FSX run under the other 7 cores, leaving the one core for Windows and whatever else FSX needs to throw at it. I really don't understand how any of this works, but having it set at 254, seems to be a sweet spot for me. I tried running it at just 14 as some suggested on another site but saw better results with 254.
 
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