Ahh, why didnt you ask before tana
. Here's my closest guess without pulling it off the card (reconstructed it from the scrap copper). The actual copper plate that I used was a 4" wide, 10" long, with a thickness of 0.025". I think that's ~22 gauge if you go by wire gauge. It was sold as hobbyist's sheet metal and was the only size of copper sheet metal that my local hardware store carried (lucky me
). Off hand I'd say this is the thickest to go, but it definitely does the trick
. The copper piece that I used on my core I just eye-balled. Judging by the rest of the strip left that I cut, I'd say it was 21mm square, but anything 20-22mm square would work fine I think. As far as the the actual plate goes, here's a blueprint displaying some more of my photoediting "skillz"
(used GIMP on the text
A few things to note. First, the picture isn't directly to scale because it's not a direct overhead shot, but it's the best picture of my 7800GTX that I have. The dimensions are pretty accurate, and the tilde (~) signifies that my cutting was off with a tolerance of +/- 1mm at the most. The X is the mark where I drilled through the heatsink so that the fourth screw could connect to the motherboard. Even so, I can't tighten the screw all the way or it will press the heatsink against the PCB and components. However, leaving it ~1mm unscrewed does add extra support for that lone corner, so maybe it's a good idea to keep it in the design. The bottom half row you cut into where the chips end, and bend up and down alternately right where the chips end. The vertical side you have to bend up about 1/2 to 2/3 out to allow room for the Go 7800GTX's PCB. I've found it best to bend up and down alternately, but on those that you bend down, bend the entire fin slightly up, and those that you bend up, keep it straight. This makes sure that the fins do not touch any video card or motherboard components. EDIT: A final note is that you must cut the heatsink so that it stops before the connector to the motherboard (which is right under the "PUSH HERE"), and that it must stop before reaching the upper screw. Hope that helped guys!
Don, is your card stable at such low volts and clocks? Amazing that you didnt get anything out of it.