ATI CrossFire

With the resolution limited to 1,600 x 1,200, I figured that I may as well take a look at one of CrossFire’s big selling points – super-high FSAA. In CrossFire mode you can push the anti-aliasing all the way up to 14x and that’s exactly what I did. With 14x FSAA enabled, the sweet spot seemed to be 1,280 x 1,024 – if you pushed up to 1,600 x 1,200 the frame rate became unplayable. It has to be said that playing Half-Life 2 at 1,280 x 1,024 with 14x FSAA looks absolutely awesome!

During the course of testing Valve was kind enough to release the Lost Coast, which gave me the chance to see shader model 2.0 High Dynamic Range lighting as well as 14x FSAA. Bizarrely loading up the Lost Coast brought back the motion blurring problem when I employed FSAA, but only when I ran it full screen – running the game in a window showed no problems at all. Even more bizarre was the fact that the next day the motion blurring problem had disappeared once more - clearly there's a little more work to be done with the driver.

So, going back to my original question, was CrossFire worth the wait? Well in its current guise probably not. In my opinion ATI should have waited for the R520 to appear before launching CrossFire, then there’d be no resolution limit, and the performance would most likely rival the best that nVidia has to offer.

Of course the problem is that ATI has pitched CrossFire as an upgrade path for existing Radeon X8xx users, so the company had to produce said upgrade path. However, I can’t see anyone that’s running a compatible card upgrading to CrossFire – not only would those users have to buy a master card to pair with their existing graphics card, but they’d also have to buy a new motherboard to house both cards. When you factor in the cost of both motherboard and graphics card, I think that most users would rather buy a single R520, or even switch camps and go for GeForce 7800 – either way, the result will be better performance and no resolution limit.

Evesham has promised to get me an R520 based CrossFire system in the next couple of weeks and I’m looking forward to pitching it head to head with a 7800GTX based SLi rig. Then I’ll know definitively whether ATI’s dual GPU platform was worth the wait.




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