Not entirely certain from my observations of this tag but I seem to see that this tag is always linked to other tags such as hard drive or graphics card or seems to be relatively broad, I was thinking would it not be best to break it down into specific performance issues such as slow drive performance slow CPU performance or graphical and sound performance for instance?
Well, I certainly agree with you that performance is a horrible tag.
In part, this is due to the fact that performance-related questions are always horrible troubleshooting questions which don't result in a solution.
If anything, I would get rid of the tag because, as you've pointed out, the scope it covers is simply too broad to be helpful. But I would prefer not to take any action at this point.