I ran a quick test after my build and saw that the inside 5770 hit 100Â°C and kept climbing when maxing out the Unigine Heaven benchmark. After a minute or two of those types of temperatures I took out one of the cards and ran a single until my cooling solution showed up in the mail on Friday:
A pair of Arctic Cooling Accelero 1 Rev. 2 coolers.
The single card with the stock cooling idles around 40Â°C and hits 70Â°C under load, with two cards in Crossfire using stock cooling they idled at 65Â°C and under load as stated it shot up to the 100Â°C range as noted above.
I got rid of the plastic junk attached to the cooler to start:
And then lapped the surface of the inside cooler, this is not an easy cooler to lap. I then cut the coolers down by around 1cm in order to fit nicely into MacBane, I took my time with a pair of shears and got some pretty good results. I sanded the cut end of the fins (not shown) to get rid of any sharp edges or potential metal splinters or fragments.
I cut the VRM sinks to size and started putting both cards together.
Something important to point out: If you use the stock spacers that come with the cooler there will be a 1-2mm gap between the cooler's base and the GPU die as seen in the image below.
This will likely give you a bricked card if you try to run it like this, so I made some smaller spacers out of PVC tubing and was good to go (Stock on the left, homemade on the right).
And here they are ready to go, pics benchmarks and temperature updates to come shortly now that they are back into MacBane.