Aye I do agree that higher flow is beneficial to waterblocks.
BillA's testing has shown us that. However, do look at some of the C/W vs. Flow rate graphs on O/cers.com or Swiftech's webbie.
There comes a point of diminishing returns. Once the knee in the C/W graphs has passed, the decrease in C/W in relation to increase in lpm becomes a linear progression, with a fairly shallow gradient IMO. Then further translating the C/W into real world temperatures. How much more temp difference or performance difference will you be obtaining by jacking up your flow from 5lpm to 10lpm ?
Taking for example the MCW5002
graphs.
That doubling of flow rate resulted in less than 0.1C/W increase in performance. Real world assuming an 80W temp source would be a change in 8deg. A fair amount in theory. in reality though?
I agree that high flow is definitely worth it, but at what cost?
As to the sweet spot for heatercores. I believe the
Thermochill evaluation done @ O/cers.com was what you'd be looking for.
To me, reading the graphs there, it would appear that the base trade off would be a 5~7lpm flow rate inside the rad (120mm sized rad) before once more a point of diminishing returns takes place.
But all of the above is my own personal beliefs.
I am interested to see what sort of performance you do get from it. I mean at the end of the day you can make all these theorectical comparisons and comparisons with data that is seen online, but its still doing it yourself that matters. Even if you dont get the performance that you may have initially wanted, its an experience and something that would educate both yourself and those who kept track on your work.