Nordic Hardware writes the AMD Radeon HD 4870 X2 dual-GPU graphics card will arrive in mid-Q3 2008 and that it will be cheaper than a NVIDIA GeForce GTX 280 graphics card.
ike the high-end of the preceding family, ATI has bridged two chips on one PCB. The card is highly dependent on the drivers as it uses ATI's multi-GPU solution CrossFireX for linking the performance of the two GPUs, and the drivers is suppose to be one of the bigger reasons AMD is holding off the launch until mid-Q3. The other reason is that AMD wants to make sure that it can pump out enough regular Radeon HD 4870 cards first without the GDDR5 supply becoming an issue. AMD believes that 4870 and 4850 are the cards that will hurt NVIDIA the most.
If the supply of GDDR5 chips is solid, or at least sufficient, and the drivers are adequate, AMD will present its new flagship in August at a price which is below that of NVIDIA's flagship product GeForce GTX 280. Stories are going around that it could be anywhere between $450-550. Even though it uses two chips, it is suppose to be a Cool N' Quiet card. We say that knowing that the cooler isn't even finished yet, but we also know that AMD has no intention of launching a card that runs hot and makes a lot of noise, and that the previous generation cooler was a rather good one.
The site also writes there will be a fairly big difference in clockspeeds between the Radeon HD 4870 and 4850 because AMD wants to brand the first part as high-end and the latter one more as mid-range kind.