On my MSI k8n neo4 platinum (non-sli), I replaced my stock hsf with a zalman nb47j and some as5. I had to remove two of the fins to allow for a capacitor on the video card (XFX geforce 6600 GT), but it fit better than I thougth it would (certainly better than with that ATI card). Also, when I removed the old stock cooler, I took the standoff, the [] square sticker+padding that goes around the core, and applied it to my zalman. It seems to serve two purposes, stopping electrical contact between the hsf and the exposed resistors, and stopping asymmetrical pressure from damaging the chip. I haven't heard much about this, is everyone else using the replacements without the standoff?
Here are some pics of the fit:
http://www.bl0w.net/images/auz/zalmannb-overview.jpg
http://www.bl0w.net/images/auz/zalmannb-closeup.jpg
You can just make out in this pic the black capacitor that I had to make room for.
http://www.bl0w.net/images/auz/zalmannb-topview.jpg
http://www.bl0w.net/images/auz/zalmannb-sidefan.jpg
With a fan.
I took temp reading with the stock HSF, but the fan being where it is, pretty much rules out any meaningful numbers as you have to measure from the edge - it was 32 deg C.
http://www.bl0w.net/images/auz/zalmannb-nofan.jpg
With passive cooling only (except whatever draft is coming from the video cooler- which isnt much), at 100% load, it gets up to 45.1 C max (as measured with my thermocouple from the center of the heatsink)
http://www.bl0w.net/images/auz/zalmannb-fan.jpg
With a small 40MM fan placed on the side and running on the slowest speed that a zalman fanmate 2 controler will allow, I get about 34C.
A small fan does make a large difference from my tests. With the fan controler I cannot even hear it. However, I would think that either of these temperatures are acceptable. It is not overly hot to the touch with either setup - and I cannot imaging this being worse cooling than that tiny stock hsf.
-auz