I have a tower Twinview 2MX in my cube with a 80mm base fan and the stock CPU. When playing 3D games under OSX 10.2, the heatsink on the 2MX card would get to nearly 100C, this means the chip itself was probably over 100C, this is too hot. It will reduce the life of the chip by as much as 100X, I put a Tennmax 5V fan-sink on the 2MX and it reduced the max temperature to about 80C, still not ideal, but much better than 100C. I've removed the modem card and the internal chrome grille from the base of the cube to improve airflow, and I still have a 80MM fan too.. The Apple 2MX Twinview cards get very hot in a cube, you should not run them without a fan-sink, or a monster heatsink that covers at least 1/2 of the card. I have looked into using a Zalman Copper GPU sink, or a Zalman G2 Heatpipe cooler, there are possibilities... I also just got a new PC Ti4200 card, what do you know, it will fit with only a tiny bit of board chipped off at the corner and a relocated DCDC card. I'm looking for a Mac BIOS tweak for it now.