Is it normal to have a card with fluctuating mhash?
I have put core voltage to 949mv and using guiminer.
according the software the 7970 is flucutating between 500-540mhash?
With cgminer, you should be getting 650+ from your 7970. 685 in single card setups, 650-ish in multiple.
Clean up your OS/apps. Disable unused devices in BIOS.
Downclock CPU, overclock gpu core, downclock gpu memory, undervolt vddc etc.
But you have 1125 on core which is 20% overclock so you should be getting the 20% more in mhash which is about right compared to my 7970 with 540 mhash.
I also have a Haf case (932) and the 7970 gets to 79c which I think starts to be abit high.
I have Core at 949mv, the memory is stock 1.6v or what the stock is, I'll start undervolting later.
my 2x 7950 + 1x 7970 use about 515w total incl rest of the system.