With the updated heatsink built (one more small revision to go) we took a quick picture. The Alpha heatsink was trimmed in a few places, most predominantly of which is up top where the fins are now angled to one side. This FrostyTech's old AFO technique peeking through, and while we're not going to explain this in too much detail right now, it will help this heatsink remain cooler under the thermal load of both the thermoelectric device and nVidia GPU. It also looks kind of cool, but in this case function dictates form.

On a side note, cutting all those fins at that angle is not that easy to do without distorting the fins into garbage. If anyone intends on trying this themselves I would suggest freezing the heatsink in a bowl of water so the ice, and aluminum can be cut at the same time. This way the fins can be held in place (without bending) by the ice as the blade cuts through them.

The (almost) final version of the GF4TEC heatsink only has one small revision to go through. The four flat head screws covered in frost sat about 1mm above the copper surface and unfortunately came too close to capacitors by the GPU for comfort. A quick countersink later and the four screws would be sitting flush to the surface, and completely out of the way.

The four small screws are spaced 38mm on center to fit the mounting holes around the GeForce 4 GPU. The holes in the PCB are just 2mm in diameter so it was a bit of a trick to find machine screws which would fit through. After a trip to the tool supply, I picked up a N-2-54NC tap, some drill bits and a few stainless steel screws to match. I wouldn't recommend drilling out the holes in the PCB as who knows what trace lines are running by there which may get destroyed.

Running off of a regular 400W power supply for copper block quickly gets covered in frosty and reaches an unloaded temp of -15 degrees Celsius, not too bad. We were expecting the thermally loaded temp to be around 10 degrees Celsius or so. Below ambient is really what we are shooting for, not below zero, or at least not just yet ;-) A small neoprene gasket we should hopefully help the temps drop even further - but I really doubt we'll see thermally loaded sub-zero temps with this little guy running off a standard computer power supply.