Did some more research. No mixup on my part - however a monster mixup on the part of the retailer! Completely wrong specs on the 6770 - no idea which card they were mixing it up with...
Given that the 6790 has the same core as the 68xx series, it initially sounded promising (i.e. BIOS hack to re-enable the disabled stream processors), but apparently AMD have done a proper laser-destroy (what a waste eh?) to prevent the unlocking that I've already done to all my 6950s
What is more important is that the research I did led me to find out that my disappointing-as-a-bitcoin-miner 6870 card can be made to work properly in my Mac Pro, which is currently running a 4870. This is a big deal and will save me a fortune (was considering spending £350 on an Apple-specific 5870)...
Dude apple specific, buy a cheap motherboard and make a linux(or er um acquire windows) rig
My business uses exclusively Macs. I've got 11 in this office I'm sitting in now.
However, just for the lulz, I've also got phoenix running on my main workstation (Mac Pro) which is netting a monstrous 80-90 MH/sec
The rest of the 6 GH/sec are from the dedicated mining rigs. You may have seen my 4 frame rigs in the 'pictures of your mining rigs' thread... Right tool for the job is my motto, hence the dedicated miners use Linux.
What I was getting at was that I've bought one 6870 for my dedicated miners, found it wasn't particularly great, but can re-purpose it as the main GPU in my Mac Pro, which is currently a weak 4870. I'll get a substantial upgrade to my Mac without having to fork out for an expensive Apple-specific card. The Apples aren't used for bitcoin mining (other than to take advantage of the Mac Pro when it'd not doing much else).
I am far too old for operating system religious wars, but I can assure you that the cost of the time lost if I were to switch all the OS X boxes to Windows or Linux would massively outweigh the increased upfront cost of the Macs (other than the Mac Pro, which *at the time* was the cheapest dual-Xeon workstation-class box around).
For dedicated mining, though - Linux all the way. Why the hell would one choose anything else, unless one was only expert with Windows? The only argument for Windows mining boxes, AFAICT, is that the overclocking utilities are more mature and have more functionality than the Linux ones. As to the OS X utilities.... rofl! I absolutely love Mac OS X, but I'm not blind to its shortcomings.
Incidentally, I read in another thread on this forum a while back how 'Apple had really screwed OpenCL' - given that OS X uses OpenCL internally, and without any overclocking or tuning of the GPU, I'm getting nearly 90 MH/sec out of an Apple-clocked (i.e. underclocked) Radeon 4870... perhaps the OS X implementation of OpenCL isn't as bad as most think? Not wishing to start a flamewar here, of course.