We have an application that uses OpenGL, and historically it has run lousy on ATI cards, although results have been different depending on card/driver combo. We're trying to put together a test machine on a very low budget, where we can swap in different ATI cards and test them. I was wondering if anyone has a good knowledge of the different ATI series, and what cards I should buy to get a broad swath of the different implementations. Is it enough to buy one card in the Radeon HD series, one card in the Radeon X series, and one card in the FireGL series? And will these be able to cover the "mobility" implementations in laptops (we don't want to have to buy a laptop because you can't really swap cards there)? Also, are there any articles you can point me to that talk about this? I've perused ATI's site but haven't really found much intended for hardware testers.
As an addendum to this question, we're not as interested in benchmarking/speed as in just getting our app to work right with all possible cards. According to user feedback, with some cards, our app will just crash, and in others textures will not be rendered properly. On some the picking mechanism doesn't work, etc. So we're not really looking for an OpenGL testing/benchmarking software. Our app is the test software. We want to test our app against different hardware. So how many cards do we need to get, and which ones, to kind of "comb the area" of the primary hardware categories?