These cards originally had 1024 shaders with 16 compute units. This one is showing 896 shaders, so it has 2 compute units disabled. I read that they used to disable them in the BIOS, and that modding your BIOS could potentially enable the other 2 compute units.
A while back I spent a fair bit of time messing around with some tools, trying to mod this one. I was unsuccessful. I also compared my BIOS to other peoples' BIOSes, both ones that failed and ones that succeeded. From what I can tell, all of the cards that couldn't be modded were lacking a certain entry in the BIOS. So have the chips themselves been physically modded in these cards?