How to Set Processor Affinity in Windows 7 and 8

These days, almost everybody has a multi-core processor. One thing that many Windows users don’t know is that you can set which processors are processing certain tasks. Knowing how to set processor affinity in Windows 7 and 8 is a quick tech trick that may really help you to run certain applications much faster.

Changing processor affinity settings is a quick and straight-forward procedure, which is actually similar in Windows 7 and 8. You just have to access Windows Task Manager by simultaneously pressing the Control + Alt + Delete keys on your keyboard and then clicking the “Start Task Manager” button. This will bring up the task manager.

Now that you have the task manager up and running, make sure you are on the processes tab as seen above. Next, you can simply right-click on the process that you want to change the affinity for and then click the “set affinity” link. This will bring up the processor affinity dialog box. You can see this below.

At this point, you can use the check boxes to determine which processors you want working on the task. In my example above, I am setting the processor affinity for my Firefox browser I have open. One more thing I want to note is that I don’t have 8 cores on my processor. My processor is a quad-core Intel chip with hyper-threading. For those who don’t know, hyper-threading, through virtualization by the OS, makes a single processor look and act like a dual-core chip. Either way, it is nice to have control of these virtual cores.

How is Processor Affinity Useful

Setting processor affinity on a task can be helpful in two pretty distinct ways. First, if you have a process that is using too much processing power, you can limit the process by only allowing it to run on a few or maybe even just a single processor. One example of this is if you have to render a video. However, you also want to play a game while this video is rendering. In this case, setting the video rendering down to only 1 processor will be helpful.

We can use this same example of rendering a video to show how you may want to use processor affinity to speed up the rendering process. In this case, you can make sure that the rendering software is able to use all cores. If you have any other processes running that are using a decent amount of CPU resources, you could then set these processes to use only 1 core. I also want to point out that an alternate way of doing this is to set the process priority a bit higher for the rendering process.

There are some additional considerations you may want to keep in mind. First, it’s not a great idea to change affinity settings for system processes unless you are really sure what you are doing. Next, the biggest benefits of changing processor affinity will come from resource intensive processes. For example, video editing software, sound editing software, engineering programs, and games are usually processor hogs. The last thing to keep in mind is that the affinity settings you specify will last only while the application is open. Once you close an application, its affinity settings will go back to default.