Remember how we told you that Eastern sources claimed that RV770 has 800 shader processors, not just 480 shader processors? When we look at the slide presented to us by a reliable source, we can only conclude that they were right. AMD evidently planted the stories of 480 shader processors (it's not uncommon for AMD/ATI to plant stuff). The slide tells us three things about both Radeon HD 4850 and 4870. First of all that they both sport a whopping 800 shader processors, but also the clock frequencies and they're individual calculation capacity measured in FLOPS. We've already told you that Radeon HD 4850 will launch at 625MHz and that AMD will clock the 4870 at at least 100MHz more, the slide says 750MHz.
Each shader shader unit is capable of 2 FLOPS, and since we now have 800 units, this means that Radeon HD 4850 with its 625MHz will hit exactly 1TFLOPS. That should explain why AMD/ATI chose that specific frequency. Radeon HD 4870 with its 750MHz core will have 20% more processing power available and hits 1.2TFLOPS. A decent quad-core processor can do up to 100GFLOPS. This is certainly a slap in NVIDIA's face. AMD's mainstream chip can do more FLOPS than NVIDIA enthusiast chips, and AMD's coming high-end chips will pack twice the FLOPS...