AMD has been on a roll lately with its Radeon 4800 series GPUs, and with the official introduction of the Radeon 4870 X2, it can now claim the world's fastest 3D gaming card.
The Radeon 4870 X2 combines two of AMD's fastest GPU, the RV770, each clocked at 750MHz on a single graphics card for a total of 1,600 stream processors. It is also the first card to offer 1GB of GDDR5 graphics memory, which supports higher data rates than GDDR3. Asus, Diamond Multimedia, Gigabyte, MSI, Palit, Sapphire and several other board makers will offer Radeon 4870 X2 graphics cards for around $550. These should be available immediately. AMD also announced a dual-GPU version of the Radeon 4850 (625MHz GPUs, 1,600 stream processors and 2GB GDDR3 memory), which will be available in September at around $400.
The Radeon 4870 X2 competes directly with Nvidia's GeForce GTX 280. When Nvidia launched the GTX 280 and GTX 260 in June, it said the high-end cards would cost about $650, but you can now find them for significantly less.
Given the strong performance of the Radeon 4850 and 4870 (also launched in June), it is little surprise that dual-GPU versions would post impressive scores (several enthusiast sites jumped the gun and posted previews last month). The final reviews confirm that AMD has grabbed the lead in performance--at least for now. The difference is clear, especially on demanding games such as Crysis at high resolutions with high-quality settings.
The Radeon 4870 X2 and 4850 X2 can be used in CrossFireX mode (two cards), but the performance here did not scale as you would expect. In the press release, AMD states CrossFireX will deliver about three times the performance of a single Radeon 4870 graphics card on "some games," but few games really take advantage of the extra GPUs, and in some cases, a single Radeon 4870 X2 graphics card outperforms three GPUs. Eventually drivers and games will be better-optimized for CrossFireX and Nvidia's SLI, but since the Radeon 4870 X2 provides plenty of horsepower for nearly all current games, it's hard to complain too much about CrossFireX.
AMD ATI Radeon 4870 X2 reviews: