Just check before you buy that there will be physically enough room in your PC...
Newer cards can get rather big. Also, what power supply is your PC fitted with, if you get a lot better card than you had it may require 2 power leads fitted and some serious poke to run it..
If your case is a slimline type, will a newer (more powerful) card put out too much heat?
Overheating will cause no end of trouble!
Apologies if you are fully aware of these pointers!
