Mounting a CPU Cooler? The Heatpipe Direction Might Matter

[Apoptosis]

Mounting a CPU Cooler? The Heatpipe Direction Might Matter

Today we will revisit a recently reviewed cooler, the NH-C12P from Noctua, to see how the mounting direction impacts the cooler's performance. Noctua thought are performance numbers were off since we installed the cooler with the bendings of the heat-pipes facing up. Noctua told us the cooler usually performs quite a few degrees better if you put it the other way round or turned by 90°. Which direction is best? Read on to find out.



Article Title: Mounting a CPU Cooler? The Heatpipe Direction Might Matter
Article URL: http://legitreviews.com/article/741/1/
Pricing At Time of Print: $69.90 plus shipping

[gwolfman]

Interesting. So why do you get the better results with the only configuration that they don't recommend? That just doesn't make sense to me at all.

[Apoptosis]

Interesting. So why do you get the better results with the only configuration that they don't recommend? That just doesn't make sense to me at all.

Trust me it doesn't to me either... lol

[martini161]

i guess more of the heat is concentrated in the heatpipes? maybe it has to do with turbulance and airflow

[bubba]

It is baffling, I know. The 'up' an 'back' temps are rather close, closer then I was expecting. Going into the testing I expected to see large gaps, 2+ degrees, between the orientations; that would have put the temps closer to how the NH-U12P (the tower cooler) performed, and where we were told they should be.

I even went as far as sticking one of the older tested coolers in the system and re-tested it to see if I got the same temps. The results were with in .2 degrees of what I had previously for that cooler.

[gwolfman]

Interesting. So why do you get the better results with the only configuration that they don't recommend? That just doesn't make sense to me at all.

Trust me it doesn't to me either... lol

So has Noctua commented on this story yet? I'm curious to see what they have to say now.

[DMB2000uk]

I hope they don't blacklist LR for this, I like Noctua products and want to see them reviewed here.

Dan

[gwolfman]

I hope they don't blacklist LR for this, I like Noctua products and want to see them reviewed here.

Dan

I don't see how this could cause a blacklist. It's not saying anything bad or wrong about the product. Simply that LR happened to find better results with a non-recommended installation orientation.

[DMB2000uk]

I guess they would have to be being very tetchy to avoid LR in the future, but my reason for thinking they might is that LR didn't find the improvements in performance Noctua was looking for.

Dan

[Apoptosis]

I hope they don't blacklist LR for this, I like Noctua products and want to see them reviewed here.

Dan

If a company would consider black listing us for something like that I'd stop working with them myself. We are not the only site that had numbers that Noctua didn't agree with as they questioned Virtual Hideouts results as well if you read the update at the very bottom of this page: http://www.virtual-hideout.net/reviews/ ... dex3.shtml

Virtual Hideout said it was due to some funky thermal compound, but didn't show the new numbers.

Noctua has read our update of course and replied with this:

First of all thanks a lot for re-testing the cooler, this is greatly appreciated.

Quite frankly speaking, I'm completely puzzled with your results. Maybe there's something wrong with your sample. I'll discuss this with my colleagues and come back to you next week in case they can come up with any explanation.

They are confused and so are we. I've been in contact with Arctic Silver and am getting new thermal compound sent out to us as ours is actually kinda old. Arctic Silver sent out our new thermal compound on July 8th and it was sent ground mail, so it won't arrive till July 14th. After it arrives I'm going to ask Shane to take a third and final look at the HSF with the new batch of thermal compound.

Tracking Number: 1Z AT2 797 03 7698 188 2
Type: Package
Status: In Transit - On Time
Scheduled Delivery: 07/14/2008

[DMB2000uk]

I think I was just over reacting when I posted the first time

Seems a bit silly to think they would do something like that now >_>

Dan

[gwolfman]

Lol ^^^^^

It seems like they're pretty serious about getting this worked out, which is good.

Btw, what thermal compound do you recommend? I've used Arctic Silver for a long time, but I'm sure there's more out there now that could be better. Isn't OCZ's supposed to be pretty good? Any recommendations?

[DMB2000uk]

Tuniq TX2 is what I recommend, according to reviews and a bit of testing by myself it seems to be the best (widely available) performing thermal paste at the minute.

The best bit is that it doesn't need any cure time.

Dan

[FeRaL]

Man, I love a company that is responsive to the community and is willing to go the extra mile. Bravo Noctua!

[gwolfman]

Man, I love a company that is responsive to the community and is willing to go the extra mile. Bravo Noctua!

I agree I'll consider them for my next heatsink purchase

[gwolfman]

Thanks Dan, I'll check it out

[Edgy]

Yes, the direction of the heat pipe might matter and what it depends on is the wick technology used within the heat pipe. A heat pipe contains a small amount of water. The heat pipe also has some sort of wick which runs its length against the outer wall. The process is that the heat source heats the water which causes a phase change (water to steam), the steam rushes to the tip of the heat pipe at hundreds mph pulling the heat with it. The steam condenses onto the wick which covers the inside edge of the heat pipe. The wick returns the water to the heat source via a capillary process.

So here’s where the orientation of the HSF may matter. There are basically four wick technologies -- grooves, wire mesh, powered metal, and fiber. You can’t tell from the outside of the heat pipe which type of mesh is employed, but it does matter. Turns out grooves work best in a vertical orientation (for gravity assist) with the heat source at the lowest point of the heat pipe. However, for horizontal applications, powered metal wick structure outperforms the others. Now regarding the Noctua NH-C12P CPU cooler under test, I suspect its heat pipes use groove wick structure and if that’s the case, there’s a big problem. Looking at the photos, there’s no way to orient that HSF to get the heat source to the bottom because its heat pipes kinda loop.

[gwolfman]

...the steam rushes to the tip of the heat pipe at hundreds mph...

hehe Are those pressurized? Cos' if not, the last time I boiled water that steam didn't shoot upwards at hundreds of mile per hour.

[gwolfman]

Oh yeah, any more news on what Noctua had to say about this?

[Apoptosis]

no sir