When my friend added an extra card to his system, he had the same issues - it showed, and would run, but at 5-10% of what it should.
After trying a few things and asking for help here we had nothing. That's when we thought we'd go for a clean install of OS - that did the trick, not sure what caused the issue though.
One thing to try is remove all drivers, then use the catalyst removal tool to chase out any ghosts - and re-install.
Anyway, hope you get it sorted
K.
Thanks for the insight, I'll give it a go
This is always my first step as well - I often have problems with a system or rig that has a few GPUs and when I go to add another, or tinker with certain things, I run into issues. Low hashes, lack of recognition, etc. Often a fresh reset with reinstalled drivers tends to show the best results.
Other times I have a lot of success by playing musical chairs with the GPUs. Some of my motherboards just don't like certain GPUs in certain slots, further they won't "talk" if they aren't risen, some won't talk if they aren't on the ground. It's really just playing mix and match with proprietary hardware.
My best efforts to avoid these problems usually occur when I construct everything together and do a fresh install as opposed to trying to modulate it later.
