Yeap same here. While one easily sits on 480-490 MH/s out of the box rest struggle to reach 460 MH/s with seriously bumped core clock. Really baffling, but there you are. Default clock is 960/1250. Version for whole batch is 912-v276-032 r7950 tf 3GD5/OC BE. Built on reference 7950 PCB with 2 6pin PEG connectors. When underclocked memory sits on 800 MHz. I have primary, separate GTX580 which is not used for mining. In such setup memory can be underclocked even lower as mining VGA is not used to display content on the monitor.

Noise is deafening with fan running constantly over 3300-4000 rpm. Border line for silent operation is 2800 rpm, but it is impossible to mine BTC with such low fans. Temp just shuts up past 80++ in no time.

Weakest point of pretty much all 7950 (but MSI TF in particular) is cooling. With 80 mm fans there is simply no way of keeping the noise down with enough air pumped. I have one TF slapped with 3x120 Scythe 1200 fans 2 on top and 1 hanging on the edge pumping air under the shroud roughly where VRM section is located. This one is relatively quiet. Remaining TF mounted in classic tower case without any additional cooling make massive racket with fans constantly 3500+ and temp not exceeding 80 on core and 83 on VRM. My only question is who the hell thought that 80mm fans are good enough to cool VGA. My GTX580 is also MSI TF3, but with 120mm fans. It is brilliant, brilliant, sublime card, even when pushed to the absolute limit it is pretty much quiet with absolute negligible fan hum when loaded 100%.

Thinking about watercooling all miners, but cost is a bit prohibitive. Maybe I will slap Prolimatech's MK-26, with guaranteed drop of ~15C degrees it is cheap way of squeezing more MH/s with less noise.