How do I cool this NORTHBRIDGE!?

blake · Post by **blake** » Mon Sep 24, 2007 12:03 am

Any ideas how to cool the stock asus heatsink/heatpipe on the Northbridge (circled in the picture). This thing is burning hot to the touch on stock voltage. Mobo is Asus P5N32-E SLI and CPU cooler is Thermalright HR-01 with fanduct.

There is only about 3/4" of clearance above northbridge as the cpu cooler gets in the way.

I was thinking some sort of 40mm spot fan? Not sure which brands are quiet, and where/how to mount it?

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studo · Post by **studo** » Mon Sep 24, 2007 1:22 am

Flip it 90Â°. So that it follows your airflow.
Click it off, and get some glue, for the purpose.

or create new clickon fasteners

AuraAllan · Post by **AuraAllan** » Mon Sep 24, 2007 1:45 am

Try taking off the heatsink and turn i 90 degrees as said. Before you put the heatsink back on the chip make sure to clean both chip and heatsink and reapply TIM.

blake · Post by **blake** » Mon Sep 24, 2007 2:22 am

Good idea to mount the fan so it blows towards the back of the case.

But glue it to the heatsink fin? Will the high temp not melt the glue??

The fan I ordered (Scythe Mini Kaze 40mm) does not come with any fasteners to jurry-rig... and twist ties don't seem too secure!!

nick705 · Post by **nick705** » Mon Sep 24, 2007 3:21 am

I wonder if the root of the problem here is the HR-01 plus duct combination - virtually all the exhaust airflow will be drawn in through the front of the HR-01, bypassing the NB heatsink, and also the VRM heatsink is buried under the duct with the exhaust fan sealed off. I wouldn't be surprised if it's dumping heat back *into* the NB via the heatpipe.

If it's a real problem, you might consider a conventionally mounted fan on the HR-01 and lose the duct, so the exhaust fan can at least stir some air around across the back of the motherboard area.

I haven't seen such a setup before, and I'm really just thinking out loud - the chipset on that board is notoriously hot, so it might cope less well than some others in a similar situation. Having said that, if everything's working OK it might be nothing to worry about anyway...

thejamppa · Post by **thejamppa** » Mon Sep 24, 2007 5:50 am

Getting bigger sink wouldn't be much of improvement. HR-05 Sli could be aligned so air flow which goes theu HR-01 goes first thru HR-05 but that would rise some CPU temperatures when pre-heated air would go thru sink.

You could get Nexus 80 mm and aligned it with zip ties attach somehow so it blows towards NB and see how it likes that. Scythe Mini Kaze 40mm fan and attach it on NB could be another choice.

SilentKev · Post by **SilentKev** » Mon Sep 24, 2007 6:11 am

OK, we all agree that the NB heatsink should be turned 90 degrees. You might also consider replacing it with something taller (like one of the Zalman NB heatsinks), but you would have to cut away part of it to get it under the CPU HSF.

As for airflow, there's a 120 mm fan to the right in the image. I would make some sort of partial duct to deflect that fan's airflow towards the NB. That in itself might be enough.

nick705 · Post by **nick705** » Mon Sep 24, 2007 8:38 am

SilentKev wrote:OK, we all agree that the NB heatsink should be turned 90 degrees.

Apart from the slight problem that there's a heatpipe connecting the NB heatsink to the VRMs - you can't see it on the photo, but it's there (unless it's been removed). Rotating the heatsink would be impossible without cutting the heatpipe, although if the VRMs are in fact heating up the northbridge that might not be such a bad thing (at least for the NB, maybe not so good for the VRMs).

I rather doubt turning it through 90deg would make much difference anyway - the fins are quite small, and in any case there's no point realigning the fins if there's no significant airflow to align them with in the first place. As I see it, the whole problem here is a lack of through-flow across the components that need it - the fan duct effectively moves the main exhaust outlet forward several inches, stranding the VRMs and to a lesser extent the NB itself in hotspots out of any direct airflow.

I suppose something like the Antec Spot Cool might do some good but, as I said, I'm not sure how much of a problem it really is anyway - it's not uncommon for the 650i to get scalding hot, and as long as it all works and doesn't melt down into a heap of silicon slag, it might actually be nothing to worry about...

SilentKev · Post by **SilentKev** » Mon Sep 24, 2007 9:21 am

nick705 wrote:Apart from the slight problem that there's a heatpipe connecting the NB heatsink to the VRMs - you can't see it on the photo, but it's there (unless it's been removed). Rotating the heatsink would be impossible without cutting the heatpipe, although if the VRMs are in fact heating up the northbridge that might not be such a bad thing (at least for the NB, maybe not so good for the VRMs).

I suppose something like the Antec Spot Cool might do some good but, as I said, I'm not sure how much of a problem it really is anyway - it's not uncommon for the 650i to get scalding hot, and as long as it all works and doesn't melt down into a heap of silicon slag, it might actually be nothing to worry about...

Good catch nick about the heatpipe. Yeah, if you increased the airflow directed at the NB heatsink that would help, but then you need to get that air out of the case. If the airflow is active enough wouldn't it get drawn into the CPU airflow? Is there any other way for air to escape this portion of the case?

I created a duct once to cover a CPU heatsink, but I made sure that it was larger than the heatsink and only covered it partially so that some of the air around the CPU area could be pulled into the exhaust flow as well. I think that directing airflow to the NB and then modding the duct or adding a new exit path for the air around the CPU is necessary.

cmthomson · Post by **cmthomson** » Mon Sep 24, 2007 11:59 am

This is the major problem with all the motherboards that tie the NB, SB and/or VRM together with heat pipes. They are all designed around the stock Intel HSF which blows down onto the motherboard and through all those fins.

Any high-end tower HSF (HR-01, Ninja, Ultra, Noctua) is designed for airflow parallel to the motherboard towards a case fan (top or back), and leaves those NB/SB/VRM radiators with no airflow.

Some approaches to solving this: add fans, add ducting, use a downward-blowing HSF (such as XP-120).

On some of the high end motherboards, the VRMs have a very high phase count, and there is extra copper on the back of the board, so the VRMs don't need any heat sinks on top. With these boards (eg, P5WDH, DQ6) the heat pipe and radiator gizmos can be removed, and the NB can be cooled with an HR-05 or other NB cooler.

bonestonne · Post by **bonestonne** » Mon Sep 24, 2007 2:57 pm

actually, don't change the direction of the NB cooler.

it sounds crazy, but look at the heatsink for a minute. air is being pulled into that duct from all directions, making the upward flow of air better, as it travels between the fins to the heatsink, and then through the cooler out of the case. I know i'm crazy, but if you rotate the cooler, than temps may not change at all.

remove the duct from the HR-01 and see how well it performs, or if you can attach a fan to it like the Ultra 120-eXtreme. because of that duct, changing the direction of the cooler at this point will do nothing. rotating the cooler will only help if the duct is removed.

think of the path of airflow with this, the rear exhaust fan is ducted, so its not going to affect a heatsink in the same way.

Max Slowik · Post by **Max Slowik** » Mon Sep 24, 2007 8:34 pm

Yeah, there's no way that assembly is going to be rotated...

Burning hot to the touch isn't bad unless the thing crashes because of heat issues. About the only thing that's going to be super-easy and silent is for you to remove the heatsinks and apply a premium thermal interface material to it. Actually, another thing you can do is duct some of that intake fan air over to it.

blake · Post by **blake** » Mon Sep 24, 2007 9:57 pm

Thanks for all the input!

Okay, so I will not touch the NB heatsink, especially since it will involve removing the heatpipe that is attached to etc.

I agree. The problem is that intake air (front fan) is blowing straight across to the HR-01 (which in effect in the exhaust port since its ducted). It I place my hand right along the motherboard (near the NB), the air is stagnant.

Will a 40mm fan solve this problem? What if I mount a Scythe Mini fan sitting flat on the NB, blowing UP away from the motherboard.. Wouldnt this hot air be sucked up thru the HR-01 fins, and out of the case?

Alternatively, I could strap a 40mm fan on the right side of the NB (in the picture) blowing towards the back of the case (left). But this would be less efficient since there is no exhaust once the air hits the back. But at least it is stirring up the heat!

Thoughts?

nick705 · Post by **nick705** » Tue Sep 25, 2007 5:18 am

blake wrote: I agree. The problem is that intake air (front fan) is blowing straight across to the HR-01 (which in effect in the exhaust port since its ducted). It I place my hand right along the motherboard (near the NB), the air is stagnant.
....

Thoughts?

"starting to shout and jump up & down, waving arms around now"...

1. Lose the duct!
2. Lose the duct!
3. Strap a 120mm fan to the HR-01! Use the one on the front of the HDD cage if you don't have a spare!
4. Report back when you've done that! If it doesn't help, we can look at other options!

The 650i northbridge is always hot! It's not a problem if everything works!

Solid Snake · Post by **Solid Snake** » Tue Oct 02, 2007 11:23 am

1. Lose the duct!
2. Lose the duct!
3. Strap a 120mm fan to the HR-01! Use the one on the front of the HDD cage if you don't have a spare!
4. Report back when you've done that! If it doesn't help, we can look at other options!

Wrong.

His setup is good right now. He's got his fan EVACUATING air, not just blowing it around. Also because there's space between the fan and HS, he's not getting a pathetic donut shaped pattern of airflow and the noise that comes with it. He's getting FULL airflow over the entire area of the HS!

KEEP the duct!

sanse · Post by **sanse** » Tue Oct 02, 2007 12:16 pm

a 40mm fan directly on the heatsink of the nb would work great. you might also consider a big fan hanging from a zalman bracket over the pci-area of the motherboard blowing air towards it. that worked for me.

autoboy · Post by **autoboy** » Tue Oct 02, 2007 1:49 pm

What about removing the back panel cover. This will allow air to come in past the usb ports and stuff, which will help cool the vrm. Since they are all connected, cooling one off will help the others. That is free and might be worth a try.