Performance issues running an old game or application on your modern PC? Try setting your CPU affinity. This tutorial will show you how

If you have a dual or quad core computer and you want to run older games or applications, then in some cases you may experience degraded performance or crashes. Sometimes these problems can be solved by setting CPU affinity / processor affinity for the affected application. CPU affinity, what's that? This refers to how many CPU (Central Processing Unit), 'cores' an application runs on. Dual and quad core processors have two or four processing units on one chip! If your game or application was written before dual and quad core systems were commonplace, it may not have been tested properly on these systems and therefore suffer performance problems when run on more than one processor core. To solve this problem, we can make the software run on only one processor core.

Setting processor affinity is a little more fiddly than changing compatibility options. We've tried to make the process as easy as possible but it may be difficult for less experienced users. We recommend that you watch the video on understanding file paths if you have difficulty with some of the terminology in the video.

Please wait a few moments while the video loads. When loading is complete, press the play button on the video control panel below the video to start playback.

The affinity.txt document mentioned in the video can be downloaded here. Right click on the link and choose "save as" then place the file on your desktop or somewhere where you can easily access it when following the tutorial.