stay away from the msi twin frozr. the cooler is not as good as gigabyte windforce. for voltage overclocking you need a cooler like the gigabyte windforce, his iceq , sapphire vapor-x or sapphire dual x . also there have been lots of user complaints that the card is overheating even at stock speeds because of improper TIM application at the factory. the quality control is quite poor. one user got two faulty cards and returned it and got a visiontek HD 7970.
here are the cards worth getting
sapphire HD 7950 Boost (850 / 925 boost)
sapphire hd 7950 950 mhz edition
gigabyte hd 7950 windforce (900 mhz)
his iceq hd 7950 boost (850 / 925 boost)
remember if you want the full performance of HD 7950 (925 Mhz) with the boost cards you have to max out the power options slider to +20% else the performance will be lower due to clock throttling. these cards can run at 1.05 Ghz at stock voltage and 1.15 - 1.2 Ghz with voltage tweaking. also they are capable of keeping temps around 70c or lower. Edited by raghu78 - 9/14/12 at 7:55pm