MCW-6000 or MCW-6002?
 

I've been reading procooling's review of the MCW-6002 and it was concluded that the MCW-6000 (3/8") actually performs better than the MCW-6002 (1/2") at flow rates of 1.5GPM and above, so basically the 3/8" version performs better when paired with a powerful pump like the MCP650.

I'm going to be using the MCP650 in my setup, but I'm also going to have a Fedco 2-342, a chipset waterblock (MCW20), and a GPU waterblock (MCW50) as well as the CPU block. I was wondering if all this added to the loop would decrease the waterflow below 1.5GPM, to the point where it would actually be better to go with the MCW6002 instead of the MCW6000?

Everything else is still going to be 1/2". I got 1/2" adapters for both the MCW20 and MCW50. Smart move or no?

3/8 recommended with the MCW6000

Well you save yourself the trouble of using larger tubing and the adaptors by using the 6000. Before 1.5GPM they're both the same, and I doubt you'll get much better than 1.5GPM if you get there at all. Let factors other than performance decide this one for you.

Yeah, I may just stick with the MCW-6002 because I already bought the tubing and the adapters. I chose to completely convert to 1/2" because I figured that it would make upgrading to a future performance waterblock easier.

I'd use whatever your pump is. Converting is a PITA, and the difference in performance is pretty insignificant.

The higher pressure of the 3/8" block is supposed to give marginally better performance than the 1/2". You'd need a hell of a pump to do better with 1/2" tubing. But ask Bill A. He's the source of knowledge for all things Swiftech.

He already got his answer from BillA ;)