I bought my XFX 5830 first. I had it overclocked at 985/250 with fan at 80% and I was getting with phoenix anywhere between 280 and 300mhash/sec.
I moved my computer into a new case that has 4 large fans (old case only had one) and I installed the Saphire 5830. I do have the Saphire hooked up to a 2nd monitor.
Using MSI Afterburner I can get the XFX 5830 to run around 280-295 but I end up having alot of issues with the Saphire.
If I overclock the Saphire to the same 985/250 with fan at 75% (which is what the XFX is running at now inside the new improved case) it will put bars up on my second monitor and lock up my system.
If I overclock it to about 875/1000 fan still at 75% I can get it stable but it runs at a horrible rate of 130-180mhash/sec.
This is happening in both phoenix and GuiMiner.
Here are my settings for phoenix:
-k poclbm DEVICE=0 VECTORS BFI_INT FASTLOOP=false AGGRESSION=13 WORKSIZE=256
I do have two copies of phoenix for each card, with the second card using device 1 but the other settings are the same.
With GuiMiner I'm using the -v -w 256 flags. It looks like I can get close to the same rates of about 250-270mhash/sec on each card but the Saphire will sometimes drop down to as low as 5mhash/sec for as long as a minute.
Also the Saphire, when I am running it at 875/1000 it's GPU usage will constantly go up and down by as much as 30%-40%. The XFX card does not do this.
Currently I am using the newest ATI Catalyst Drivers with SDK 2.4 and my system is Windows XP SP3 Pro 32bit
Please any help would be greatly appreciated cause this is driving me crazy!!!