hello people, just reading up on pumps and comparing power so for the D4 it has max. Flow rate: 1400L/h where as my DDC plus has 600L/h i belive. i shall have a dual rad/aqua extreme cpu block (resrictive)/ gpu block/north chip block. i dont think this is going to handle it ! what do you think? should i get a D4?
It'll be fine. The D4 might offer more performance, but not much at all. If anything you'll be more hindered by ambient temps.
The actual flow rate that you get in your loop is never anywhere near what it says on the label. The pressure (head) that a pump can generate is more predictive of flow than its flow rate. Moreover, flow rate is, well, overrated in other respects too. Don't worry about it.
You would certainly regret getting a D4 over a DDC or D5 Vario for that matter for sound levels along as they are really quite noisy in comparison. Plus once you stick a few blocks into the equation you will see that the L/h start to become slightly irrelevant to the over all performance. Check out the Pump Performance Linky