While thumbing through the news this morning I found an interesting read on some 5870 (RV870) rumors that are showing up. Theo Valich (formerly of the Inquirer and TG Daily) took a look at these an injected some logic into the mad ramblings that abound.
He points out that the going claim that ATi will add 25% more shaders just to get a 50% performance boost flies in the face of the way ATi currently engineers their GPUs.
Theo also makes a bold claim that the RV870 will have a 256 bit memory interface and not the 512 bit one that most seem to think will show up.
To read more take a look at Theo's new blog here.
However, there is just one thing that does not hold ground in the story - and that is that RV870 should use 512-bit memory interface and GDDR5 memory. I may be forced to eat my own words, but no, ATI RV870 will not bring 512-bit memory controller. RV870 will feature much improved 256-bit memory controller, and it will offer bandwidth of some 150-200 GB/s per GPU. When you combine the two GPUs, possibly on the same substrate, you will get 512-bit memory controller...in a way. 512-bit memory controller with current GDDR5 memory (900 MHz QDR, e.g. 3.6 "GHz") yields 230 GB/s. And that is the amount of bandwidth GTX280 would have if nV went for GDDR5 instead of older GDDR3 memory.
Nvidia's next-gen part will however, bring 512-bit memory controller coupled with GDDR5 memory, offering insane amount of bandwidth - 200-250 GB/s, to be more precise.