Well technically there is a specific AMD heatsink so you would be better off getting the right one for the 6990M but the differences aren't huge so you should be able to use the Nvidia one without issue. One of the differences is due to the GPU die position on the AMD cards. The first image below is the 560M with the die sitting parallel to the card but the AMD die sits diagonally. The heatsinks have a black sticker on the plate that sits up against the die (I'm guessing to help keep the thermal paste on the die). You may just need to remove the sticker on your heatsink so none of it sits against the die. The AMD heatsink also has a few extra bits on it to help cool the chips. You will also find that the Nvidia heatsink for the 560m will be rated to 75w (there should be a sticker on it somewhere) and the AMD heatsink will be 100w (from memory). This is probably the biggest reason to find the correct AMD heatsink.  [IMAGE] [IMAGE] Another thing to remember is the heatsink mounting bracket is different between the cards. This is the x-bracket that fits to the back of the GPU and allows the heatsink to mount to it. Make sure that the replacement AMD card comes with one as you can't use the Nvidia one on an AMD card.         
Hello All, Another question for all you Alienware aficionados.. since this is my first one, I have lots of questions. I recently got a M17x R3 in surprisingly good condition, so far it has just needed a battery (and I hope) cpu/gpu fans. Other than that everything is working great. It came with the Nvidia 560m gpu.. runs fine, no issues there.. my question would be.. if I want to install the AMD 6990M gpu, would the gpu cooler be the same, or would I need to find one for AMD, and of course.. would that swap even be beneficial? Thanks I’m advance! Ryan
M17x R3, GPU cooler question