Quote Originally Posted by Navanod View Post
An X flow means single pass...the liquid flows along the length of the rad once, from one corner to the other corner diagonally. Its less restrictive but the heat transfer would be less
Note that the inlet and outlet would be on different sides of the rad

A standard BIE is 2 pass...the liquid flows from one side to the other along one set of tubings, and then back to the same side along another
More restrictive, more cooling and both barbs are on the same side which may or make not make life and tubing routing easier
X-flow is very restrictive and has good heat tranfer when use with high cfm fans due to itīs compact fins and the tubes a very flat thereby exposing the coolant to more surface area. But i believe the BI-Extreme will beat it when both are compared due to itīs double pass and itīs thicker in width than the X-Flow. Everything depends on what you want to cool and which will be easier for you to configure in your loop.