ATI has made a remarkable comeback over the past year with enticing GPU releases that match, and sometimes surpass, Nvidia's offerings for performance, power consumption, and value.
However, that doesn't mean Nvidia has been ducking the entire time, as they promptly responded to everything ATI threw at them. For example, at the beginning of this year, when ATI recaptured the top performance with the dual GPU Radeon 3870 X2, Nvidia quickly responded with an even more impressive and powerful card. The GeForce 9800 GX2 followed the same dual-GPU path, using Nvidia's SLI technology and a pair of GeForce 8800 GTS 512 GPUs.
Two months ago, Nvidia launched its latest generation graphics cards, which consist of the GeForce GTX 280 and the GTX 260. However, the Radeon HD 4870 and 4850 have proven to be excellent counterparts, offering a similar level of performance at a fraction of the price.
From today's perspective, the GeForce GTX 280 is the fastest available GPU graphics card, while the standard Radeon HD 4870 is not too far behind. The Radeon costs less than $ 300, however, while the GTX 280 sells for around $ 450, which gives AMD a generous amount of leeway on pricing.
To get the most out of this situation, AMD made the $ 559 Radeon HD 4870 X2, which follows the same premise as the previous generation X2 cards and glues two of the latest Radeon GPUs onto a single board. A terrifying prospect given the performance of today's graphics processors. The Radeon HD 4870 X2 offers an enviable combined processing power of 2.4 TFLOPS, 60 Gtexel / s bilinear filtering and, thanks to the high-clocked GDDR5 memory, a memory bandwidth of 230 GB / s.
The Radeon HD 4870 X2 is also more sophisticated than the 3870 X2 when it comes to connecting the two GPUs. The integrated GPUs communicate using a feature called CrossFireX SidePort, which provides additional bandwidth between the two GPUs. The total connection bandwidth of 21.8 GB / s provides roughly three times more bandwidth between the GPUs than the older 3870 X2. Although this feature is in the hardware, it is not enabled by default as AMD states it is not currently required and can be enabled later on the drivers in case future titles require the additional bandwidth.
When it comes to card pricing, keep in mind that buying the 2 GB version of the Radeon HD 4870 X2 is cheaper than buying two Radeon HD 4870 1 GB graphics cards. This could give users an added incentive to spend all of their hard earned cash at once rather than preferring a Crossfire configuration and leaving the second card on the way as a possible upgrade.
Today's test device Radeon HD 4870 X2 was manufactured by Diamond and has a full 2 GB of memory. We're told that a 1GB version could emerge at some point, while a slightly slower and more affordable Radeon HD 4850 X2 also includes 1GB of storage per GPU (2GB total) and is slated for release later this month.