Value and Conclusion

Whether scalable multi-GPU setups are a boon or [long-term] bane, is a debate that will go on for ever. Multi-GPU setups such as ATI CrossFire and NVIDIA SLI, provide the convenience of letting you step up performance on an incremental-upgrade basis, without having to replace the graphics card with something more powerful, and in some cases, more expensive. On the flipside, running multiple graphics cards gives linear increases in power consumption, and noise-output. You are left at the mercy of games and 3D applications, to support the multi-GPU standard you are using. In applications that are not optimized for the standard, no performance bonus is obtained, the additional graphics cards turn vegetables. CrossFire takes away the convenience of performance scaling when the 3D application is running windowed.

ATI CrossFireX has been a technology that is always open for improvements. Over the years, the technology has matured many fold, and has garnered support from the game developer community in a decent measure. With this article we wanted to see first-hand how AMD's newest kid on the block, Radeon HD 4890 works in a pair. Thankfully, several of our game tests were receptive to the multi-GPU standard, and responded with decent performance increments, which scale up with increases in resolution. At 1920 x 1200, performance increments of 92.3%, a near-perfect scaling is observed, which is impressive indeed. Against competing high-end, single-card solutions that fall in the same price range, HD 4890 CrossFire holds up pretty well when it comes to performance, though you should look at several things when opting for HD 4890 CF: NVIDIA's GeForce GTX 285 is a fast single-GPU accelerator that frees you of having to bother about whether your application is optimized to get the most out of it, and ends up consuming lesser power. It is 21% slower overall, and is priced significantly lesser. GeForce GTX 295 and Radeon HD 4870 X2 are both dual-GPU accelerators that have much smaller board and acoustic footprints.

AMD leaves you room for two more graphics cards, provided your motherboard and power supply support it. Speaking of power, you will be surprised to notice that a pair of HD 4890 accelerators consumes nearly the same (in fact less) amount of power as a single Radeon HD 4870 X2 accelerator, on peak and average scales. Supposed improvements in the manufacturing process in which the RV790 is make, could be a likely explanation. We just couldn't stand the noise of one HD 4890 card, and had to literally punish ourselves with that of two. At 51.3 dBA, you may consider a case with noise dampening, a pair of noise-cancelling headphones, or quieter cooling solutions. In all, we are delighted with what this roughly-500 Dollar solution has to offer as far as performance goes, though we have our gripes when it comes to its acoustic footprint - that of Bigfoot, and the seemingly minor glitches today's multi-GPU setups face, which hopefully they will tide over with.