For ages, multi-GPU technology has been this giant wet dream for many computer enthusiasts who have yet to get enough money together to try it out. The allure of using two graphics cards to make your game run effectively twice as fast means that you won’t have to break the bank to keep your rig updated – that was more or less the way it was sold in the beginning, with Voodoo making cooing noises to enthusiasts and starting off the craziness in the late 90’s.
Over the past fifteen years, though, not only has it not caught on as much as graphics card manufacturers hoped, but its still something only available to high-end users, or people who planned for it when they built their machines. SLI and Crossfire are still a pipe dream for most.
But recently Nvidia and AMD have made motions to try fix their technology once and for all and make it really attractive. Nvidia has had moderate success with this since the Geforce GTX400 series, but they’ve actually been trying to fix it since the G80 family was kicking about. They recently achieved completely smooth SLI performance with the Kepler architecture and have been pushing the technology ever since. It now makes sense even using two smaller Geforce cards together, because SLI and frame metering works well enough to give you around 90% more performance.
AMD has not had it so well, though. Crossfire has been broken for a while despite the company’s best efforts and its still a mystery as to why they didn’t pick it up earlier. It may very well be that they assumed that most people would put up two cards in Crossfire, dial up the settings as much as they could to get nearly 60 frames per second on average and then enable V-Sync to remove frame stutters.
And that’s exactly what most people did – use V-Sync to plaster over the fact that the technology just wasn’t working properly on its own. To be fair, Nvidia had this same issue with SLI and people used the same fixes there as well.
In fact, it took Nvidia’s driver and engineering team to release FCAT (Frame Capture and Analysis Tool) and focus more websites on measuring frame latency and variance to finally force AMD to address the issue. On 1st August they released a beta driver (Catalyst 13.8 Beta) that fixes Crossfire performance for single-monitor users playing games that use the Direct X 10 or 11 code path. It works remarkably well, but there’s still some polishing to be done to get it completely right, not to mention that they also need to address games using DirectX 9 and multi-monitor users as well.
Is Crossfire enough to save AMD’s reputation with gamers? At this point it raises them back into competitiveness with Nvidia if you were thinking of going multi-GPU and certainly compared to the GTX690, the HD7990 is much, much better. It has more memory, better performance and will also power those UltraHD 4K monitors better because of the larger frame buffers.
But when it comes to pairing two separate Radeons together, Nvidia has the upper hand because their cards generate less heat and consume less power. Arguably if you’re a power user you don’t care about that, but its an important factor to some, and still counts against the red team for now. The Geforce GTX700 series also has the benefit of being slightly cheaper and better-positioned in the market.
I expect, though, that these fixes, coupled with their next-generation HD8000/HD9000 series will bring them back to the same success they had with the HD5000 series – there they whalloped Nvidia to tiny pieces and had the upper hand in timing, pricing, performance and power consumption. They can easily get back in that groove now.