Quote Originally Posted by Mirage
You can use cards with a faster AGP speed than 4x on your computer without problems.
Actually...
Many newer cards have different voltage requirements (cards started at 3.3V, then went to 1.5V, and then 0.8V) and the AGP pin layout on the cards also changed. Be wary when buying a card...in fact, I would suggest sticking with only those that are explicitly 4x compatible.