Heatpipes...

Do heatpipes work differently when oriented in different ways? I ask because my current brand new CPU cooler, a Scythe Mine-Rev B is performing well below the supposed ability it has on this review I read (and based my purchasing decision on):Scythe AMD K8 Heatsink Temperature Comparisons - SCMN-1100 FrostyTech Review

What I interpret that chart to mean is that with an AMD CPU outputting 125W of heat will be cooled to 20.4°C above ambient temp.

That would be great if it actually did that...

My CPU is an Athlon 64 X2 4200+ S939, which according to AMD and 'Core Temp' outputs a maximum of 84.4W, yet it idles at around 45-50°C, and under load, gets very close to the maximum safe temperature of 69°C, and I often have to stop what I'm doing to let the CPU cool (usually Crysis, or bizarrely Silent Hunter 4, which is far less demanding I would have thought). There is no way the air in the room is 50°C.

Now AFAIK, heatpipes are filled with a 'vapour' which is supposed to heat up, and circulate the heat along the whole pipe (because heat rises). If I'm right, then surely the 'sideways' mounting of the cooler in my tower case will compromise this? If the heatpipes are not working as well as they should be then this would explain why the Scythe cannot cool something that should be WELL within its abilities.

I would have thought that most computer cases are tower cases of some kind, so I can't see why there are so many CPU heatpipe solutions if they don't work very well when used in most cases.

I really can't figure out why my cooler is so poor considering the CPU it's dealing with and the alleged performance figures in that review. If I'm right about heatpipes, then do tell me, so I can find an alternative cooler which doesn't use them.



OR



Tell me what else could be causing such poor cooling results please :help: .
(Already cleared out dust, and ensured good airflow)

Thank you.

No it shouldn't matter.
Heat pipes are filled with liquid, as the liquid heats up it boils (turns to vapour) to change state from liquid to gas requires a lot of energy (heat) the vapour then flows along the heat pipe to a cooler section where is condenses back into a liquid releaseing the stored energy.
the cleaver thing is the the insides of the pipes are are not smooth but are ridged or simular, this non smooth surface draws the liquid along it through cappilery action back to the "hot" end of the pipe.
(there shouldn't be enough liquid in the pipe for gravaity to have any major effect.)

It does sound like there's a problem as your temps are a bit too high.
check that the fan is working
try reseating the cooler

your idle temps are way too high so it could be a sensor reading error or a badly mounted hs (as a comparison my Opteron 146 is running at 26C here as I surf & iirc my x2s didn't run much hotter).
BIOS up to date?

Thanks for that Pob225, sounds interesting.

I'll reseat the thing, apply more thermal paste and see if it helps.

Quote:

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Originally Posted by Pob255

the cleaver thing is the the insides of the pipes are are not smooth but are ridged or simular, this non smooth surface draws the liquid along it through cappilery action back to the "hot" end of the pipe.

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Whilst I agree the sensible thing first is to reseat the heatsink, this isn't true of all heatpipe designs, many lesser models are simply filled with a liquid and rely on gravity to return the medium to the hot end.

OP should be getting better temp though. Go for a reseat, re-applying the TIM too. Check airflow is ok.

Capillary action should be employed in the heatpipes (using a special coating on the inside to facilitate the flow of the liquid back to hot area) - but as the post above, this is not always the case.

Hopefully you can reduce the temps a bit.

Then you can answer your own question...try the case (and therefore the heatsink) in a horizontal and vertical position by simply laying the case on its side.

Post back your results.

Quote:

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Originally Posted by Silent Shark

Thanks for that Pob225, sounds interesting.

I'll reseat the thing, apply more thermal paste and see if it helps.

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Sometimes less is more. You only need enough to fill the airgaps. Too thick and it creates a larger heat barrier.