Quote Originally Posted by MikeMK View Post
Gabe - I tried my MCW60 on my 5870 last week, and found it made v.poor contact with the GPU. I fiddled around with it a bit, but it would only contact one small part of the GPU. Not sure if the GPU is a mm lower vs. the shim or something, or do we need a new mounting bracket for this card? BTW... glad you are doing a full heatsink solution for this card, hopefully it doesnt take too long to land over here in the UK!
I checked the specifications (from AMD reference 3D Models)

The normal distance from silicon surface to pcb is:

4870X2 model for reference: 2.26mm
5850 and 5870 models: 2.41mm

From our MCW60 specs, the normal distance from surface of the copper base platform to bottom of the legs is 1.85mm; on specs, that leaves a 0.56mm gap between feet and PCB, which is standard.

There could be several reasons for a poor contact between this particular MCW60 and the silicon, listed below are the most plausible explanations:

1/ The copper base plaftorm was over-lapped and is out of specs (possible) - Nominal distance should be comprised between 0.76 and 0.63mm
2/ The chrome hold-down bracket is bent downwards at the corners (from earlier mounts), lifting the entire block upwards (likely)
3/ Combination of both of the above


Diagnostic & remedies:

1/ Carefully measure the height of the copper base platform with a caliper or dial indicator to verify compliance with above specs - If below 0.63mm, remedies are to RMA block, or implement #3 below.
2/ Place a straight edge on the hold-down bracket, and verify bow. If excessive bow is observed, remedies are to request bracket replacement from customer service (michelle@swiftech.com) or implement #3 below.
3/DIY immediate remedy: place the block feet down on 120~200 grit dry/wet sand paper (tape edges of paper preferably on glass table). Holding the block flat, rub the feet in a circular motion for a few minutes (2~5mn).