EK Supreme vs. Swiftech GTZ Extreme

both will be about the same. water cooling technology has reached its limits.

at this time, all high end water blocks perform about the same. it doesn't matter anymore which one you pick.

I think in Martins last waterblock test it showed the EK pulled ahead a few C

In a single block loop, the EK Supreme will pull ahead by roughly 1C. In a multiple block loop, go with the GTZ.

it doesn't matter what block it is on if you have reached the limits. this is not a scenario where performance are bottlenecked. if that is the case, you will barely even have a delta T. the fact that all high end blocks share similar load temps and different delta T, means that that is the limits of the block itself.

To further expand what I said would be like this:

Right now we have near reached the limits of the designs for current water blocks. More efficient designs only appear to increase temps by a couple of degrees. The only way to break this wall is either to use a material for the water blocks or radiators or to use a new type of coolant.