The only way to know for sure is don't take anyone else's word for it. Test it for yourself the numbers will speak for themselves.

Hear hear, webmedic! Right on! The only way to know for sure is to test the complete system for yourself.

However, for those who are unwilling to buy lots of different components to find the best fit... I do feel that the basic principles hold true. Higher water flow (CFM) through a given waterblock will improve it's performance. Lower water velocity (meters per second) through a radiator will improve it's performance.

However, with a good waterblock and radiator, I believe that even a low-end pump will give good performance. Just don't skimp so much that the pump ends up being a low reliability solution. Nothing sucks more than burning up your $200 CPU because of a $20 pump. DEATH TO RIO! :D

I probably was a bit short with people, but I feel that it is important to get concepts correct and to be precise with language. I have no problem with the comments that were made here about cooling systems overall. However, taking the observations and ascribing them to waterblock performance only was incorrect and so I felt I should clarify.

As a parting comment, how believeable would it be if I told you that some heatsinks worked better with low CFM fans than with high CFM fans? Would that seem reasonable?

To give an example of what I'm talking about here are some pics and temps:


http://community.webshots.com/album/35111553UecmAe

This is all with a 150gph pump I've used the ehiem in the same setup wich you can see in one of the pics but the newer pics are all using the 150 gph pumps.

I'm keeping a spreadsheet with all kinds of temps as I change things. The ehiem 1250 317gph pump gives the exact same temps as the 150gph pump and no it's not rio. I've tried two of them and they are one of the few pumps that actually raised my temps (by 2c).

The purpose of a forum is to exchange ideas, and difference of opinion can be healthy. When emotion gets involved when making a point, things can get interesting. But thats life, hard to seperate the two at times.

I am new here and you guys don't know me from Adam. I am open to other ideas and experience from more knowledgable folks, but when I say I did something and these are the results I got, I ain't making it up. Ask me how I got them and fault me for procedure if you can, but I won't accept it can't be. It's also nice to learn from engineer types why something I did happened so I can understand it better.

Anytime I decreased the flow with my system, my temps increased in the same controlled ambient setting. If I increase airflow through the radiator, my temps decrease slightly too. Sure temps of 1-2C are not much, but I want the best temps possible without a pelt, and these little gains all add up.

pH, my point exactly. run a 50cfm delta on a heatsink instead of a 27cfm and you will get better temps.

run a 500gph pump and you will get better temps on the waterblock than a 270gph pump. the rad mightn't like this though, which is why we need to run parrallel rads