Passive heatsink for P4 northbridges?

Metaluna · Post by **Metaluna** » Thu Nov 06, 2003 8:20 am

I have an Asus P4C800-E Deluxe motherboard (Intel 875 chipset) which has a passive northbridge heatsink on it. This heatsink gets extremely hot (too hot to hold your finger on for long), especially when running the memory bus at 400MHz DDR. I'd like to replace it with a beefier passive HS, but the only one I know of is the Zalman NB47J, and that appears to only support through-hole mounting, whereas most recent Intel-based motherboards seem to use a hook-and-loop type retention (i.e. spring-loaded hooks on the heatsink attach to wire loops soldered down on the board).

So has anyone successfully attached a Zalman to an Asus P4C board, and if so does it work any better than the stock heatsink?

Fabool · Post by **Fabool** » Thu Nov 06, 2003 8:50 am

I would be more concerned if it didn't get hot. If it's hot, it means it's doing its job transferring the heat away from the northbridge.

I doubt the Zalman would be any more efficient but if you want to try you could use the thermal addhesive that comes with it. The downside is that it's permanent, if I remember correctly. You might also be able to remove the loop mechanism from the standard heatsink and mount it on the Zalman.

MGP · Post by **MGP** » Thu Nov 06, 2003 10:35 am

I agree with Fabool's post. In many times, I've found stock heatsinks on mobo chipsets run relatively cool -- that is, until I replace the gum-like thermal material on these heatsinks with some good 'ol AS3. Suddenly, I've found that the better thermal conductivity has made the heatsink significantly hotter to touch (much like Metaluna's Asus situation).

MGP · Post by **MGP** » Thu Nov 06, 2003 10:37 am

Oh, and BTW, Metaluna: remember that the NB47J should not be used with thermal adhesive on a northbridge and that Zalman does not recommend users to thermally adhere their heatsinks to chipsets with raised dies (commonly on Intel chipsets like your 875 and my 850E). Just wanna caution you before you make your decision.

lenny · Post by **lenny** » Thu Nov 06, 2003 11:18 am

Metaluna wrote:I have an Asus P4C800-E Deluxe motherboard (Intel 875 chipset) which has a passive northbridge heatsink on it. This heatsink gets extremely hot (too hot to hold your finger on for long), especially when running the memory bus at 400MHz DDR.

What CPU HSF are you using? I've come across posts where people say that with the Zalman 7000 and the Thermalright SLK900 HSF, you get some bonus airflow over your Northbridge HSF. May be something to consider?

Post by **Ralf Hutter** » Thu Nov 06, 2003 11:48 am

Why do you think it's too hot anyway? Are you having some sort of problem that you think is being caused by the NB running too hot?

I certainly have had no trouble with any of the passively cooled Asus and Intel 875/865 boards that I've been using, all with DDR400 RAM and run between 200MHz and 250MHz.

If you're just concerned that it feels too hot, I wouldn't worry about it. I doubt that Asus and Intel would be releasing these boards with passively cooled NBs if they didn't think it was a viable solution.

ez2remember · Post by **ez2remember** » Thu Nov 06, 2003 11:51 am

How about using thermal glue to attach a VIA socket 370 passive cooler? I doubt this thing will rip-off the mobo, it's only made of aluminium and is pretty light. It is much beefier so it should work very well..

Cooler Master VIA passive cooler

Metaluna · Post by **Metaluna** » Thu Nov 06, 2003 12:30 pm

lenny wrote:What CPU HSF are you using? I've come across posts where people say that with the Zalman 7000 and the Thermalright SLK900 HSF, you get some bonus airflow over your Northbridge HSF. May be something to consider?

I'm using an SLK900U with a 90mm Zalman fan currently. This is a narrow heatsink so the fan overhangs the sides quite a bit, however the orientation is such that the overhanging sides are not overlapping the northbridge. Instead the fins of the SLK900U are pointing towards the NB, so heated air from the CPU is probably blowing down over it (though this is probably better than no air at all). Also with the motherboard mounted in a minitower case, the NB heatsink's fins are oriented horizontally, against the flow of convection.

Metaluna · Post by **Metaluna** » Thu Nov 06, 2003 1:24 pm

Ralf Hutter wrote:Why do you think it's too hot anyway? Are you having some sort of problem that you think is being caused by the NB running too hot?

Possibly...I have been unable to get my P4-2.6c past 2.8GHz without failing the Prime95 Torture Test, even with the CPU fan maxed out. I'm using PC4000 (250MHz) memory so I don't think that's the problem. It could just be that I have one of the few 2.6c's that won't hit 3GHz but I figure if I can cool the NB better I can eliminate some variables.

Anyway, there are only a few occasions when I'd feel the need to OC the processor, so I'm pretty happy with the system as-is. It's more of an intellectual exercise at this point than anything else. I'll try rigging a temporary fan to blast the NB with cool air and see if that makes a difference.

If you're just concerned that it feels too hot, I wouldn't worry about it. I doubt that Asus and Intel would be releasing these boards with passively cooled NBs if they didn't think it was a viable solution.

Yeah I'm probably being overly sensitive to this issue. Now that you mention it, I have heard several accounts of people successfully overclocking the FSB with the stock heatsink. I do observe that the heatsink Intel uses on its boards looks a lot more massive with a more open pin fin design than that of the Asus, though.

Riffer · Post by **Riffer** » Thu Nov 06, 2003 2:09 pm

Not up to speed with the latest boards, but have you tried cooling the clock-generator?

lenny · Post by **lenny** » Thu Nov 06, 2003 2:20 pm

Metaluna wrote:I'll try rigging a temporary fan to blast the NB with cool air and see if that makes a difference.

Try what I did - open up the case, use a room fan and blow directly into the case while you try to overclock. Eliminate any doubts about heat once and for all.

Have you tried playing around with the memory latency?

pingu666 · Post by **pingu666** » Fri Nov 07, 2003 7:11 am

bluetac a lil fan to nb and see if it helps

klingon · Post by **klingon** » Sat Nov 08, 2003 11:05 pm

Metaluna,

Please check out below discussion thread if you have not done so, yet.

http://forums.silentpcreview.com/viewtopic.php?t=7470

wumpus · Post by **wumpus** » Sat Nov 08, 2003 11:26 pm

Try what I did - open up the case, use a room fan and blow directly into the case while you try to overclock. Eliminate any doubts about heat once and for all.

Yep, that's one of the first things I have people do, if they think heat is a factor in their problem.

A giant house fan blowing 1,000+ cfm across your motherboard does a great job of decisively answering that question-- there's no doubt about what is and what is NOT a heat problem after that.

Passive heatsink for P4 northbridges?

Passive heatsink for P4 northbridges?

Re: Passive heatsink for P4 northbridges?

Re: Passive heatsink for P4 northbridges?