The problem with the newer cards is that the prices of them just shoots way up beyond reason, and then a year or so later it is like a third of the initial cost. I have one lowly XFX 4650. It doesn't put out like the big ones, but it cranks out about 2,880 units/points a day running on a 450w power supply so it doesn't suck down much juice. That's like 1,051,200 units a year out of that one little card. Still just knocks the socks off any quad out there, and much much cheaper to purchase too. :-) And while it doesn't put out like my 4850's, it is still a pretty marvelous item when I look back several years to when I was running a herd of processors and getting much less that the 2,880 units a day. We get pretty spoiled on performance now days and forget what the performance leaps are in a short time span.

My 4850 runs 9,600 units a day or 3,504,000 or so units a year, over three times what the xfx 4650 will do. So those gpu's are definitely worth their weight in gold when viewed from a cost versus output perspective. Much cheaper than buying new cpu systems. So they are the way to go for crunching rc5.

My GeForce cuda systems on the other hand are much slower than the ATI systems and suck down much more electricity too. However when compared with what the cpu systems put out, the present cuda systems still are impressive items. It will be interesting to see what the next generation cuda stuff does, and what Nvidia is going to charge for them too.