Replacing the existing heatsink/fan combo

I’d like to replace the existing heatsink and fan combo.

I note there are what seem to be four screw-holes around the processor - are they intended to secure a heatsink?

If they are, could you confirm their their dimensions? I measure them as 35mm from center to center, and square. (I can’t reasonably view Altrium files, far as I know, or I would check myself.)

My first thought is to fit a purely passive solution - a heatink much bigger than the existing unit, I would imagine secured by its fitting into those screw holes.

The processor package is only going to be touching a fairly small part in the center of the heatsink, in the center, so I’m not sure how well this will work.

If it doesn’t work well enough I would then naturally think to put a fan on top, but where the heatsink is bigger, it would be a correspondingly bigger fan - slower, quieter, longer-lived.

Does anyone have any experience in this or words of advice?

I’m looking at the Advanced Thermal Solutions web-site, I would think if something existed which I could use, they would have it. seems to work fine for the Altrium files, though I’m not sure if you can extract any useful info that way. I just uploaded the zip file.

I seriously doubt the holes are for heat sinks. The original board was going to be fanless until we managed to melt a chip during stress testing. I would guess something along the lines of alignment holes for equipment used to mount the processor on the board.

Replacing the fan is easy. The make and model has been mentioned here before. See for instance

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You get something different, I guess?

When I wrote the original post, I think I could find a viewer, but Windows only.

Oh, oh! Thankyou - vital information.

I guess then heatsinks are typically attached by a plastic mount which goes directly around the CPU, as we see at the moment. That seems unfortunate, since it limits the physical size of the mount to that of the CPU; if you’re thinking to go fanless, you probably want a large heatsink, much larger than than CPU, but you need to have enough support for it that it is physically secure.

Yes and yes - I saw the recent post about replacement fans.

However, my fan is fine : it’s rather that I want not to have a fan =-)

Measuring, the heatsink appears to be 23mm by 23mm. The plastic mount, at its largest, seem to be 25mm wide and 30mm long. The processor itself I think is square, but I can’t accurately measure the width and length. An unanswered basic and critical question is whether the dimensions I see for heatsinks are for the heatsink proper (the metal part) or for the plastic mount.

It seems quite unusual, from what I can see so far, to have an oblong (as opposed to square) plastic mount.