I took your advice and got claymore.. I now have 330 sol/s. Stock bios win7. Card is overclocked pretty nicely. A 100 extra sol/s.. intensity 7. Fan profile is similar to yours running cool at 71
The problem possibly was in intensity 8. In 280X is 3Gb video memory - it enough only for intensity 7 in Claymore 12.5. If miner runs on intensity 8 the speed will be slower because of out of memory. In my system miner don't run in intensuty 8 and 9 saing that not enough video memory. But in other system/driver it can run at intensity 8, but speed wil be much slower...
You have 330 with stock bios and overclock. I have 335 with modded bios, light overclock and downvolting. Power draw of my card lower. Speed the same.
p.s.: omg 86-90-92 degree? 0o
I setted -tt to 72, and -ttli on 80...
I have high temperature of the card because it's not only one in my system block ))))
Sapphire trix isn't let me downvolt. You said you using a certain driver?