Quote from: c33fax on June 10, 2013, 09:04:32 PM

Hi, so just fitted a brand new 7990 Radeon gpu... But when I use GUIMiner it seems every second the hash value is changin from 70 Mhash to 169 then 490 then to 'connecting...' this then repeats but with different values...

Also when I log into BTC Guild my average speed is about 490Mhah, half what this card can do....

Any ideas

There are a couple things: one could be bad settings on the card itself. Are you overclocking or using stock? Another is that it could be a faulty card.

Also, if you restart the PC does it have the same issue?