That said, look up MCW-60
Thanks for the heads up! But you think I'll blow the vrm if i only mounted some alu heatsinks on it @ 0.95v? I wish i had some numbers to work with here.
I've got 3 Sapphire Xtreme and 1 Sapphire Ref. I don't think the xtremes have heatsinks which is separate from the GPU HS.
Most non-ref video cards that don't use a full cover heatsink just has GPU core contact and uses a small-ish aluminum heatsink over the top of the VRM's. It's "passively" cooled; It relies on incidental airflow to keep it cool, which usually comes from the fan responsible for cooling the GPU heatsink.
If you're undervolting, I'm sure you could entirely forgo the airflow, and you -might- be able to get away with no heatsink either. I know when I had to fix my 5870, I used a crappy zalman heatsink + fan that was way too small for cooling the 5870 GPU correctly, and I had no VRM heatsink either. I think I was running it at something like 600MHz and 0.95v and getting 100C VRM with extreme high airflow from a delta LOUDLOUDLOUD fan. Not mining on it with no cooling shouldn't blow it up, but it'll get toasty since it only has the PCB to pull away heat