Adjusting affinity effectively improves gaming performance


Have you ever wondered how you can force affinity to multiple cores while gaming? Well here's the answer. I discovered that for a lot of my games (I have a dual core machine) only Core0 is used when gaming. With CPU intensive games like for instance Need for Speed Shift the Core0 was being used 100% and Core1 was almost doing nothing.

I came across the following program WinAFC. You can download it here:

Here's what you do next. Unpack the file to your preferred location. After you finished doing that open the affinityinput.txt file in the root folder.

For example enter to following line to make NFS Shift run on both cores.
E:\Games\Need for Speed SHIFT\Shift.exe := CPU0+CPU1 [assign=2,priority=normal]

Here you can specify the applications you want to assign affinity to.

The priority settings can be set to Unchanged | Idle | BelowNormal | Normal | AboveNormal | High | Realtime. I prefer to configure it to normal. CPU0+CPU1 means that this executable will run with affinity set to both cores. CPU0+CPU1+CPU2+CPU3 means the executable will be run on four cores if you have a quad core. And so it goes on.

Now save this file and run the executable WinAFC.exe.


Now a command prompt is executing and notice that in your system tray there is appearing a new icon.


Right click this icon. A context menu will appear. Choose settings. Next click that tab startup settings.


Now check the checkbox console minimized on start. Leave the default path of the log file default. Save the settings.

Now right click the WinAFC icon again in your systray. Choose load profile...affinityinput.txt


And you are done!! You can add the a WinAFC shortcut to you Startup folder so it starts when booting your PC. Make sure to run it in a minimized window. Then the icon will only appear in your System tray. You are going to be amazed how much performance you gain after applying affinity to multiple cores when gaming. I am amazed how smooth NFS Shift now runs on my machine compared to the normal configuration. When not changing affinity manually or by this program the game runs A LOT slower. This goes for a lot of other games as well.
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Good lord.. This gave me about 10-15 FPS gain in NFS Shift :D Just any game is running smoother with high detail settings... :)
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Senior Editor
Staff member
Made no difference to me, same frame rate, it does the same as if you were to use taskmanager, and all my processes are set to use all cores anyway. But i have an underpowered P4 with HT... so i doubt it'll make any difference to me anyway. I don't have Need for Speed though, just tried it out with other apps.


Tech Monkey
Hmm actually it does seem to help, I was getting some choppiness in NFS:Shift and after this all is fine, how odd.

EDIT: also seemed to help in CNC3 when there was a lot of stuff on map/bombs etc.


Same here it has made quite a significant difference to me. I am running an AMD system as well. It could have something to do with AMD driver support in Windows 7 perhaps. I am running a AMD64 system on Windows 7 64bit. If it isn't helping with Intel based CPU's then this could be a AMD related tweak. Just speculating here I haven't tested this on an Intel platform. The only thing I know is that it makes a nice difference for me. I have installed the AMD64 cpu driver as well.. Well Windows 7 already has multiple core support but I did that to just be sure.

Well it's nice to hear this helped improve your gaming performance that is quite cool :)
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