The great debate raging in watercooling circles these days concerns the relative advantage of "high-flow" (typified by DangerDen, Swiftech, et al, using 1/2" ID tubing) vs. "low-flow" or "small bore" (exemplified by Aqua Computer, using 6-8mm tubing).
I have been partial to the big-bore equipment (primarily due to price and availability issues) and have been much pleased with the performance achieved.
There is no denying however that plumbing 3/4" tubing can be a challenge due to bend radius constraints and avoidance of 90deg. fittings (a definite no-no for high flow performance, yet a total non-issue for the low flow camp).
I've decided to perform a homebrew, totally non-scientific experiment on Sprocket to get some first hand experience with the merits of the two approaches.
Arriving Wednesday is a box of 3/8" ID Tygon tubing, a selection of 3/8" barbs and a MCP355 pump. I also have a modded top cover for the pump which allows for better inlet positioning and (supposedly) increased flow.
Stage 1 of the test will consist of replacing the 1/2" barbs on the CPU/GPU blocks and radiator with 3/8" versions and running with the high output MCP655 pump already installed.
Stage 2 will replace the pump with the smaller, less powerful, native 3/8" 355 unit ( which is the rev.2, 18w model, BTW).
Stage 3 will replace the pump cover with the modded version and also introduce 90deg fittings wherever they will simplify/streamline tube routing.
Stages 2 and 3 may be combined depending on difficulty of installation/amount of modding necessary...
I do not have (nor am I interested in obtaining) the proper test equipment to elevate this beyond simple anecdotal evidence, so my results will be scientifically debatable, however I don't see why they wouldn't be an acceptable indication of the differences between the two approaches.
As always, I'll keep you posted.