I think I'm finally dropping my conviction that putting everything in series is the best way to approach water cooling. However, novel for me, I think I'd like to know what more experienced people would do before I buy more pieces (or break things). The loop has gone beyond simple, so trial and error will take a very long time. I think it's multiple loop time, probably with a common reservoir. I have the following things to cool CPU with ek supreme block. Modified, possibly ruined. 8800gt with full cover, second 8800gt with core only block Power supply (worst case scenario is a 150W heat dump) In the future I'm likely to add ram and chipset to this, but I haven't yet. To cool these, I have A feser 240 with scythe s-flex Two feser 120s with a san ace One, soon to be two, 18W ddcs One 10W ddc A ddc res top Soon a 120mm thin rad which might fit over the rear exhaust I'm currently using two quick disconnect fittings to separate everything on the motherboard tray from everything in the case, I'd like to continue doing this but don't believe I'm going to be able to. Case is an akasa omega. I'll try a few things tonight, but suggestions would be much appreciated. I think two loops with a combined reservoir makes the most sense, but a T line system also appeals. It seems a thin 120mm radiator with a 1000rpm fan, under a heat load of 150W, can be expected to maintain a 15 degrees delta. Source. This suggests running the 8800gt's off a single 120mm radiator. Restrictions, The psu/chipset block must have a radiator either side of it, or earthing problems exist. Or I could just leave it be. Swap out the 10W ddc for an 18W one, and call it good. Some research into centrifugal pumps suggests putting them next to each other in series is fine, so I'll move them adjacent and see if that stops tubing collapsing.