Techtree had an interview with AMD worldwide CTO Raja Koduri about the Radeon HD 4800 cards, CrossFire and some other technologies the firm is working on like Fusion. Koduri confirmed the first generation of Fusion products will basically be a mashup of a 780G chipset and one of AMD's processors and that we can expect Fusion somewhere in 2009.
TT: The move from the 320 processors to 800 (for the 4850); that's a massive jump. How did you manage to keep the cost down? Since both are based on a 55nm process.
R: Yes, we've been asked this question several times, and it's interesting that everyone actually expects that we have one magic silver bullet. But it's actually a combination of a hundred different things that all had to be coordinated to come together in reducing the price. We took the arithmetic logic unit on each of these 320 stream processors and optimized them, shrunk it down while keeping the functionality; in fact, we added functionality. We also added various instructions to it. So it's not that we removed any functionality, we added functionality. But we got a chance to optimize thanks to the 100 engineers working on this chip. They did a pretty good job of it.
TT: Were you working on the 4-series even before your 3-series was out? Were you targeting the 4-series and was the 3-series just a stop gap arrangement?
R: With the 3800 series, we knew we had an opportunity to work with 55nm. So we decided, 'let's do that in the shortest possible time without making design changes and the architecture changes'. So we took the 2-series and shrunk it down and got the power and cost advantages that you get with the 3-series. But for the 4-series -- we started while 3 was happening said, 'we have to take it to the next level.'