does anyone know if a motherboard with a heat pipe can be mounted upside down?

[muell67]

like the title says im trying to find out if it would be alright to mount my mohterboard in my cabinet upside down. I think I recall hearing somewhere that you shouldnt do this if you mother board has a heat pipe because it wont work correctly.

[Rudi]

The position of the motherboard doesn't matter.  What does is heat.  Make sure there is enough air circulation, and you won't have a problem.

Rudi

[NightGod]

Actually, it can matter with a heat pipe, because they use basic thermodynamics (they usually use a fluid inside the pipe to transfer the heat away from the CPU-hot liquids rise, cold liquids sink) to do their job. You can try it out by doing some load testing and thermal monitoring to see how things go, but as a general rule, I think it would be ill advised. Right-side up or vertical would seem the most prudent choices.

[elvis]

Actually, it can matter with a heat pipe, because they use basic thermodynamics (they usually use a fluid inside the pipe to transfer the heat away from the CPU-hot liquids rise, cold liquids sink) to do their job.

Not so, I'm afraid.

Heatpipes have nothing to do with gravity nor liquid density.

I'm not going to re-explain it in detail as it's too long winded.  If you want to know how these things work, read the wikipedia entry:
http://en.wikipedia.org/wiki/Heatpipe

Most heapipes contain a semi-liquid inside them.  Quite often a wax or oil of some description.  Or even mercury and ethonal on some occasions.

But long story short, you can mount them at any orientation.  It will NOT affect the cooling ability of the mechanism.  Notice how 99% of PCs sold today are tower configurations where heatpipe heatsinks sit horizontally.  Notice also how 90% of video cards sold over the last 2 years were AGP, and sat with the heatsink (and heatpipe) facing the floor. 

Again: heatpipe orientation does not affect it's ability to cool.  Read the wiki entry to see why in detail.

[u_rebelscum]

Actually, it can matter with a heat pipe, because they use basic thermodynamics (they usually use a fluid inside the pipe to transfer the heat away from the CPU-hot liquids rise, cold liquids sink) to do their job.

Not so, I'm afraid.

Heatpipes have nothing to do with gravity nor liquid density.
...
Again: heatpipe orientation does not affect it's ability to cool.  Read the wiki entry to see why in detail.

I have a heat pipe that shows I can mount it a few ways, but not in others.  With other (aka high quality) heat pipes orientation might not matter, but this cheep one does. 

And the wiki doesn't say orientation doesn't matter, but that capillary forces help move the liquid.  If the capillary force can't overcome gravity, then it wouldn't work.  Since the wiki also says there are different ways of manufacturing the wicks that act as capillaries, it should be noted that different wicks have higher and lower capillary forces, with one kind of wick not able to overcome gravity.

Most heat pipes probably are able to work upside down, but definitely not all. 


BTW, my CPU heat pipe cannot work on an upside down motherboard or in two of the four orientations with a vertical motherboard (those with the pipes vertical).  That's what I get for buying cheap knock offs.  [shrug]

edit: spelling

[NightGod]

^^
That's exacly why I said "can" affect =) Yeah, if you have a good quality one, you should have no problems, but I wouldn't want to risk it on a cheap one. And I'd rather make a more expensive one more efficient by not mounting it vertical.

[elvis]

If the capillary force can't overcome gravity, then it wouldn't work.

In the last 5 years of dealing with PC cooling and in particular the popular emergence of heat pipes in a variety of devices, I've not yet come across one where the "capillary force" as you call it cannot overcome the force of gravity.  Particularly when you consider that you are talking about a change in density of only a few percent.  Such a poorly designed item could never pass the quality standards needed by motherboard and CPU manufacturers.

I would seriously hope that such poor performing devices never make it to market.  Again, I've never seen one myself, despite having seen thousands of these devices pass under my nose in the last few years.