AMD Cayman info (or rumor)

[mAJORD]

There has to be some negatives, there are rarely changes that only result in positives. Increased power consumption is already one.

I think your assuming everything is shader limited and there will be a linear increase in performance with shader increase. This has been proven wrong almost entirely this generation.

The increase from a 5870 to a 4890(same clocks) was between 30-50%
Or even the gtx 280 to 480 is around 30-50%.

http://www.tweaktown.com/articles/29...on/index4.html

This was a best case scenario because AMD got to double everything, texture units, ROPS, Shaders.

http://www.anandtech.com/show/2841/17

Drivers might have brought performance up 5% but it also brought up 4890 and 4870 performance as well.

AMD this time is going to at best increase performance by 50% because there is only a 50% increase in real shaders. There is a big but this time around.

AMD is not going to double ROPS and texture units this time around; because of this, AMD will start seeing drops off from that 50%.

Even the wildest optimist on this board beside yourself, doesn't believe an 80% increase will happen because this is the same node.

Much of the purpose of changing to a new architecture again, is trying to make those spec gains linear again. Because if their was only a 1920 shaders difference(using the same technology), their might be a 5% performance increase between the 5870 and 6970, because the 5850 and 5870 perform the same at the same clocks and thus shows, shaders are encountering another bottleneck in the architecture. Changing to a new architecture is going to help the generation pick up some gains again, but not this perfectly linear 80 percent your thinking of. Barts XT performs as well as it is, because it has the ideal configuration(encounters the least amount of bottlenecks) to get maximized performance out of the r600 - r800 architecture. AMD is not going to get this ideal architecture off the bat, as it took AMD 3 and a half years to get there.

BTW, Barts xt is clocked at 900 and not 725mhz.

can't compare HD4890-HD5870.

There was some obvious efficency lost moving to the DX11.. just look at HD5770 vs 5830 vs 4890

There's (logically) only room for improvment in efficency, as we saw with barts.

Still, I agree it will be well below 50% increase in performance if current specs are true..