I have been a Nvidia guy since my first computer. However, their newer cards/drivers have been a hassle the past couple generations or so. Recently I purchased a 470 but it blew on me within a week. Lately I have been looking at some ATI cards. I've always found it tricky to compare the two cross branded cards, when looking at cards I normally look at clock speed first but these two cards have such a variance in clock speed I cant make a judgement on gauging the ATI cards. What does the community think about these two cards and, if I were to upgrade my 9800GTX which would be recommended? If not one of these cards, which card would you recommend within a similar price range?
I have used cards from both camps. I went from a TNT2 (Nvidia) to a 9600pro, 9700pro, x1800xt, 8800GS, and finally my 5750. Basically I buy whatever I can afford that will provide me the best frame rates. I almost bought a 5600 before I realized that the 9600pro was faster.
If you want to know which is faster, then you need to look at the benchmark scores. Don't bother comparing clock speeds or number of shaders. The architectures that make up the cards are so different its impossible to compare them directly like that. Either ask on a forum and get a general consensus or look up benchmarks yourself. General rule of thumb is AMD cards are faster, cheaper, or possibly both. There are exceptions of course, and Nvidia currently still has the fastest card possible with the GTX580.
I just switched to an nvidia gtx 580 from 3 amd 5850s. The drivers for multi-gpu users are terrible on the amd side. The grass is not greener over there.
When I was comparing different alternatives, I know it sounds funny, but I listed framerates for the resolution I play at (or the next one up if that wasn't available) from the various review sites for different cards in a spreadsheet. It makes it easier to compare. You can start to average things out that way. You should also note the different features on and off have quite an impact on framerates (AA, AF, HBOA, etc...).
More than that, though, for me the AMD driver releases for the last few months gave me one issue or another with my crossfire setup. To me, I had way too much of an investment in the technology to have to deal with the monthly issues with the drivers. It seems you're better off as a single-card person with AMD. That's been my experience. All my single card AMD setups had no driver issues.