Hi guys, I just popped in to talk about my Arctic Xtreme IV equipped 290X I finished a couple months back...
So, the main problem is that the Xtreme IV doesn't have really adequate VRM cooling (only some passive cooling by the backplate through the PCB and some thermal pads directly between the PCB and the backplate), and the same is true for the memory. While the memory isn't that much of a problem, the VRM does get quite hot (it does go towards 90-100°C during gaming, though I did my test about half a year before, so my memory is a bit sketchy.)
The solution was to get the original aluminum cooling board that came with my VGA and cut it in about half, thus getting a new heatsink over the VRM chips at the back end of the card closer to the PSU connectors. (Yes, this voids your warranty in every way possible.) Now it never goes above 65 for one, and 75°C for the other. Right now it is idling with my dual monitor setup at 45°C (I mean the VRM, not the GPU, the cooling of which never posed a problem to the setup.)
I also put some small heatsinks on the memory chips, but the adhesive on a few of these gave way, so I might redo them with contact cement or something stronger, although I haven't had any overheats during my long playing hours, and I don't think these extras are necessary.
Well, anyways, the finished product is an absolute beast, it absolutely needs the brace in the package, and it almost brushes against my Mugen II. In the R4, length is definitely an issue if you want to use all the drive cages. Of course, it is not entirely silent while gaming on max, but it is on a really acceptable level of whoosing even playing a sneaking game and listening on the speakers.
Here are some shots:
The added extra heatsink is an uncoated aluminum piece without heatpipes, you can spot it in some shots between the PCB and the bottom heatsink that only cools the GPU itself
https://lh5.googleusercontent.com/-8KkSblCjYZ4/U38PaZk07pI/AAAAAAABimk/ZIApVwRkJ3A/s2048/DSC03456.JPGhttps://lh6.googleusercontent.com/-BES4qtfBq8A/U38PaZulrKI/AAAAAAABimw/JAjnB9_EUls/s2048/DSC03457.JPGhttps://lh3.googleusercontent.com/-Kvan8zPbaYc/U38PaeyKelI/AAAAAAABimo/_MyQGbE3kX0/s2048/DSC03454.JPGhttps://lh3.googleusercontent.com/-57UM9gEe0EE/U38PaTxmMjI/AAAAAAABims/xNFWqzSqR9I/s2048/DSC03458.JPG