i don't really know what stream processors are but 4870 = 800 / 9800gtx = 128.
idk if all of the 4870's have gddr5 memory but thats kind of cool. i just bought 2 more 3870's off ebay for $185+15 shipping... i don't see myself getting another card for a while. My older x1950xt is still a very capable card.
anyhow... i think im going to put the guts back in the case sometime tonight. It looks like everything on my new system is running ok. I have it @ 3.4ghz and the ram at a little over 700mhz (highest spd = 752)
* I just got the 3870's in! I have to make a change or two to the water tube when I get home and then get everything tested w\ the 2 3870's.