If you have any sort of graphics setup that relies of AMD's CrossFire technology, you'll want to download the Catalyst 13.8 beta and install it right away. Since AMD has wisely decided to enable frame pacing by default, gamers should see the benefits of that feature in any DirectX 10/11 games immediately. Based on our benchmark results, the slow-mo videos we've captured, and our own seat-of-the-pants impressions, I think we can say with confidence that AMD's frame pacing solution appears to work just as well as Nvidia's SLI frame metering. The Radeon HD 7990's frame production and delivery results look much more like what you'd get from a single fast GPU—and that's exactly the behavior you'd want.
AMD still has work to do: extending frame pacing support to 4K displays, DirectX 9 games, and hopefully OpenGL, too, eventually. Also, we refrained from testing Far Cry 3 for this article because of a lingering problem with that game. AMD tells us a fix is coming. This is just the first beta driver release with this feature, so these limitations should come as no shock.
I get the sense that AMD hopes this driver release will restore some of the luster to the Radeon HD 7990. Given how well it seems to work, I suppose that could happen. We don't often recommend graphics cards that cost nearly a grand—although, hey, this Sapphire model is down to a paltry $920. Dual Radeon HD 7970s will cost less and perform the same. However, I still like a lot of things about the 7990. We've only tested three games so far with the new driver, but at least when frame pacing is an option, the 7990 can plausibly claim to be the world's fastest graphics card. AMD will throw eight (quite decent) games in your face if you buy it, which should be a disconcertingly pleasant experience. And I still think the 7990's super-quiet cooler is a revelation, although less of one after THG uncovered some overheating issues in smaller enclosures. You'll need a beefy case with good cooling to house one of these beasts. Still, for the right setup, the 7990 could be a bragging-rights goldmine and a significant source of your daily requirement of buttery smoothness.
Before you plunk down nearly $1K on this glossy black-and-red monster, though, consider that multi-GPU cards like the 7990 are very much hardware-software combo solutions. The results on the last few pages have given us a nice object lesson on that front. Making two GPUs work well together is a constant effort that requires frequent software releases to support new games. With the Cat 13.8 beta driver release, AMD appears to be well on the road to fixing this particular problem.
But realize that literally years have passed since the first forums and tech websites, particularly in Europe, started talking about microstuttering. Nvidia claims to have implemented its frame pacing solution back in the G80 generation of cards, a claim we still need to confirm. We know AMD did nothing back then. We first talked to AMD about microstuttering nearly two years ago, for our first Inside the second article. We illustrated the problem with frame-by-frame plots at that time. Evidently, AMD did nothing. Only when we irrefutably pinpointed the problem at the display level with the aid of the FCAT tools supplied by AMD's competition did Team Radeon begin taking microstuttering seriously. Work on a driver fix finally began. With this issue exposed for all to see, the firm went ahead and released the Radeon HD 7990 to consumers when a fix was months away—and marketed the product on the basis of FPS scores, a metric multi-GPU solutions with microstuttering essentially inflate artificially.
There is a lingering question of trust here. If another issue crops up with multi-GPU configs that impacts gameplay but isn't easily quantified, will AMD do the right thing for its customers? I'm afraid I can't make any plots or high-speed videos to answer that one. You'll have to make that call yourself.