My current board is a GA-Z68X-UD3H-B3 1155 motherboard.
2600k @ stock 3.4ghz
The stock north bridge heat sink was a passive aluminum plate, approximately 2.5" X 3" and the thickness ranged from 5/16" to 3/16".
Though my NB temps we not too high. I always like to improve where i can.
As there is not enough room for a tower type cooler, i had to improvise.
I used an old school vga active cooler. It is made from solid copper and is 54.8mm (just over 2") in diameter with a base thickness of almost 7/64" (2.7mm) and just over 1/2" with the fan cover.Weighing almost twice what the stock cooler weighed.
The Spire Coolforce vga cooler i used is no longer available, but here is a similar cooler.Newegg does have other brands and colored vga coolers as well.
Dremel with a small cutting wheel. (the bit just fit into my Dremel, but wouldn't tighten down all the way.)
#2 Will it fit?
I have less than 1/2" clearance between my video card and the NB chip. I do have plenty of room as the diameter of the stock and replacement cooler are almost the same. As far as height goes, i did have to remove the fan cover. Now i have plenty of clearance.
A good way to check is to look at your sata connectors. With the video card installed, you have roughly 1/16" between the connectors and card.
#3 Making it fit.
As the push pin or bolt on holes are a different distance apart from one another, i had to drill the holes slightly larger on the vga cooler to insure that the cooler would lay flat on the chip and not be pulled at an angle. I used a 5/32" drill bit to do this.
Than when laying the cooler into place i noticed that a capacitor was in the way. I had to use the Dremel to notch out an area of the vga cooler to fit over the capacitor.
EDIT. Thanks to John Albrich for pointing out that it is a quartz crystal rather than a capacitor.
The holes through the board were too large to use push pins.
I did not have long enough machine screws to go through the mobo/cooler and still use the springs on the screws so i used some adaptor plastic washers that came with my Zalman socket 1156/775 clip kit. $5 from newegg.
New cooler installed:
Here are my before and after temps.
I used prime 95 torture test for 16 min.
Stock prime 95 @ 52c, 125f
Vga prime 95 @ 47c, 116f
Stock prime 95 @ 37c, 98f
Vga prime 95 @ 31c, 87f
All in all, it seems as though the stock cooler does quite well.
The higher the over clock the more the vga cooler will be useful at even higher temps.
I do notice the vga cooler cools faster when you stop prime 95 then the stock cooler.