I've noticed that it seems like a lot of folks like to pile extra fans into their MDDs. It has always been my opinion that the stock MDD cooling design is fairly efficient, especially with the main(big) case fan positioned right next to the CPU heatsink and effectively having a direct front-to-back path for the airflow. The dual 1.42 I recently bought had been afflicted with "fanitis" and had a bunch of fans piled in it. I think that these probably actually hindered airflow, as they weren't secured but really just laying around in the case(two stacked in the secondary ATA bay). They also made one heck of a racket-much more so than the reputably loud stock MDD. I was using the computer last night and got fed up with it, so I pulled all the extra fans and took it down to stock cooling. Granted, I'm not running an overly hot GPU, but I still have the hottest-running factory CPU(and its corresponding copper heatsink). I spent a while last night in Leopard with both cores pegged near 100% for most of the time. The CPU card never went over 120ºF, which to me is plenty cool-especially given that it's more than likely in need of a repaste. It actually ran cooler than it did with the extra fans piled in there. After I shut it down, I checked the heatsink and it was cool to the touch. As it sits, the computer has a WD 500gb ATA HDD, and I had an older IBM Deskstar("deathstar") in there for experimental purposes. It's running the stock Radeon 9000 and has a USB card. There are also two optical drives. If I really wanted to push the limits, the extra fans might serve a purpose. I know-for example-that they are a necessity with many CPU upgrades such as the infamous dual 1.8 I have now in a Quicksilver. Otherwise, though, I'm perfectly content with how the computer runs with the stock cooling. I'll re-evaluate after I install the X800, but I don't expect a huge change.