We can therefore expect the PowerVR to manage 25 Mh/S at .9w. This gives us a Mh/J of 27.7, compared to 1.8 for a 5850.
This has potential.
Color me impressed, I don't believe it will either give out that hash power or use that little power. How could they provide a chip that is more than ten times for efficient than high-end desktop versions, for a device needing less complexity than a desktop PC.
Thats exactly it. They are much less complex, which means smaller chips, which means less power consumption. Mining is a very simple operation, most of the stuff on a desktop chip (high speed RAM, ROP's, Texture Units) is extraneous and wastes power.
But I agree, hard numbers are needed. I will try and get a dev board so I can test it.
Since they are less complex, they should be oriented towards this specific process (hashing operations). Yes, I am aware mobile chips use much less power, especially in sleep mode.
According to the wikipedias, SGX545 has a 1 Gpixels/s fill rate for 2 x 200Mhz and 1W, to use such a metric that can be compared to desktop GPUs...
An HD6990 has 53 Gpixels/s rate for 2 x 830 MHz and 375W on the other hand, so 50 times fill rate, 4 times clock rate and 375 times the power usage.
So by idiot made-up math, I would say the SGX545 would be able to make HD6990 hash rate divided by 53 times 4, or
3.77 Mhash/s @ 1W? Really good, but not that extreme as previously suggested?