I wasn't sure whether this goes in the Cooling forum or the System Builders' Advice forum, so admins please move it if you feel it goes in the other. I would like advice on assembling my first water cooling system. I recently upgraded my system from a Core 2 Quad to a Core i7 system, and I am extremely happy with the upgrade, except for one thing. On my old motherboard, my GTX 470s were spaced four slots apart, giving two empty spaces between them and lots of room to suck air. Now, they're right next to each other with little breathing room, and their fans are extremely loud at load. (This might also be because they're less CPU bottlenecked, but the primary reason is not important). I began by searching for alternate air coolers, but all I could find were at least three slots wide or won't work with more than one card, so i have turned to water. My objectives for the system (in decreasing order of importance) are: Upgradability: I already have a H60 for my CPU, but I would like the option to add a CPU block to the system in the future. Ability to use the same GPU blocks on different cards: I would like to be able to reuse the blocks (for cost savings) should I upgrade the graphics cards, so full-coverage custom blocks are out for me unless I can get an insanely low price on them. Low noise: below 45 dBA (and perferably below 40dBA) at load. Price: Important, although I am willing to spend if there is a significant increase in performance for an increase in price. Lower temperatures: Although I know this is guaranteed with water compared to air, this is useful to prolong component life rather than to overclock. I have been reading all about the water cooling on this and other forums, and I priced out a system that I would like you to review. It was really confusing determining which parts are best based off reviews because I've noticed that fans of water cooling seem to be a lot more brand-loyal than of any other component, and it's easy to find two reviews with completely conflicting conclusions. I chose the Swiftech parts because they seemed to have the best prices for comparable performance, but I am open to anything. Here are the parts: ~$350 cooling system 2 x Switftech MCW82 GPU blocks Swiftech MCW35X PWM pump and integrated reservoir Swiftech MCR320 3 x 120mm Radiator Phobya noise destructor (for pump vibration isolation) 1/2* ID tubing and barbs And the picture below is how I would plan to assemble it, relatively to scale. The sharp tube angles are for ease of viewing and do not mean I would be using elbows in the loop. Now, here are my some comments on my choices: I chose the MCW35X because of the PWM control feature, so that I could automatically reduce pump speed at low load to reduce noise. I am open to other pumps, but I like the idea of automatic speed control (and dedicated controllers are relatively expensive). I have my case on a rolling cart/tray under my desk, and my setup is height constrained since I would like to keep the computer under the desk, so I am stuck with a mid tower case. Anything taller than a mid tower case will not fit, and since I can't fit the radiator inside the case, I plan to mount the radiator and pump to the cart. I am putting the blocks in parallel instead of series due to the reduced pressure drop. Also, I am feeding the MCP35X reservoir from the top due to reduced cavitation in the pump. And here are my questions and concerns: At what height should the pump/reservoir be located in relation to the other components? Does this even matter? I have no clue where to start with looking for fans. I really want them to be PWM, but otherwise I don't know what ones would be quiet and provide adequate airflow. I would like some suggestions. I would like to keep the GTX 470s' stock backplates to save cost, but I am concerned with the compatibility of the MCW82's with this backplate. I have read posts that the MCW60 was compatible but the MCW80 would not sit flush, but I do not know about the MCW82. I am more willing to mod the backplate if necessary, but I am not sure what I would need to change. I really appreciate your time, your suggestions, and your help!