[bigben2k]

#1 - reduce the area with fins (unless you're cooling one of those new quad core CPUs).

#2 - consider other options, for inlet.

#3 - consider the area where the heat source is actually located.

#4 - optimize your coolant flow for the above.
Flow path, as well as flow speed.


If you haven't done it yet, check out other designs presented here, for more inspiration.