Ask Dan: Cooling conundrums

Date: 14 October 2007
Last modified 03-Dec-2011.

 

I've got an EPoX EP-8NPA7I motherboard with the Nvidia nForce4 4x chipset, and a howling slimline 40mm fan which I would very much like to replace without endangering my board.

I've seen in several places on the Internet that this particular chipset is very hot, and I want to make sure I replace the current cooler with something that's up to the task.

The Nvidia tech department hasn't been a great deal of help, and EPoX won't help me unless I tear my computer down far enough to read the serial number off the board, so I turn to you and your unnatural ability to scrounge up technical whitepapers.

I want to know the approximate amount of energy the cooling system needs to dissipate as heat, and if possible the max allowable temperature for the chipset.

Ben

Sorry, but I absolutely cannot be bothered looking this stuff up.

Fortunately, I have a short-cut answer to this question. My current PC is a (now relatively elderly) Athlon 64 X2 box with an nForce4-chipset Asus A8N-SLI motherboard, whose chipset fan dropped dead ages ago.

+2 Fan of Dodginess

I just unscrewed the fan from the cooler assembly, balanced an 80mm fan on the video card pointed at the chip, and it's been fine for more than a year, now.

The fan's a 2500RPM-max unit; it's one of the UV-reactive ones from this old review.

A more elegant solution would of course involve an actual mounting bracket for the fan - something anchored to a rear expansion slot cover would probably do the job, or you could splash out the several-dollar price of one of those Zalman bracket doodads:

You could also get all fancy, twist off the old heat sink (it probably won't take the chip with it - are you a man or a mouse?), and stick a chunkier one on. Then, less air flow would be needed, and you could put the fan somewhere more sensible, or run a duct to a little blower somewhere, or even graft on a heat pipe solution like the ones that come standard with lots of whizzy motherboards these days.

Cooler Master Blue Ice

The best plug-and-go extreme chipset cooling option you can get today is, I think, Cooler Master's frankly outrageous Blue Ice heat pipe tower cooler. At first glance you'd think it'd be leaving a trail of torn motherboards in its wake, but it's actually apparently quite easy to install on any chipset you care to name.

If the Blue Ice cost a fortune then I'd find it hard to recommend, but it's only $AU44 including delivery from Aus PC Market here in Australia. Australian shoppers can click here to order one!

After this page went up, a reader told me about Thermalright's HR-05 chip cooler.

Thermalright HR-05

It's a hefty passive cooler (no fan) that apparently also works very nicely on the nForce4.

And it's not expensive, either; Australian shoppers can pick one up from Aus PC Market for $AU38.50 delivered.

 

I bought this PC from Aus PC Market, and it seems to be overheating in games. What do I need to buy to get this bad boy working strong?

Tony

First, make sure it's actually heat that's the problem.

Take the side off the case and point a desk fan at the guts of the computer. If bad stuff doesn't happen any more, then it is indeed a heat problem; if no amount of external ventilation seems to help, then it's probably something else.

Assuming it is a heat problem, you'll probably be able to solve it with a bit more fan power.

As you've probably noticed, the Lian Li PC-A06 case that Aus PC Market chose for this compact gaming system has an unusual layout. The computer's power supply at the bottom of the front panel, with an extension cord leading from the socket on the back panel.

The air flow in the PC-A06 is set up to work with the normal exhaust-fan behaviour of the PSU. So the single rear 80mm fan is an intake fan, not the usual exhaust.

This could be causing a problem, since there isn't anything pushing much air over the expansion-card area. The rear intake fan blows over the CPU area of the motherboard, but that air flow largely bypasses the expansion cards, including your toasty warm GeForce 8800 GTS.

I don't think it'll help much if you add another 80mm intake fan to the second fan location on the back panel, because that second location is at the bottom of the back panel, which is even further from the expansion cards.

The rear fan, front 120mm fan and PSU between them probably move more than enough air through the case too keep the computer working fine, even in an Australian summer. If it's falling short, it's because not enough of the air flow is being stirred over the expansion cards. If you fix that, you'll probably be all right.

Alternatively, you could let more air in around the expansion cards.

There are a few ways to do these two things. I'd start by removing the back-panel covers for all of the unused expansion card locations. Each of those spots will thus become an air intake, since there's more fan power blowing air out of the case at the front than there is sucking air in at the back.

To get more air to come in through the rear slots, you could swap the low-power front 120mm front exhaust fan for a medium-power one (anything from Aus PC's fan department that you can fix to a 2000RPM or higher speed will do). That'll make the computer significantly more noisy, but will also make sure air's being sucked in briskly through every hole in the back of the case.

There are lots of "slot fan" products that mount in an expansion slot location, but they're unfortunately always exhaust fans, which aren't quite what you're looking for.

Still, a medium-powered exhaust slot fan next to the heat sink of your hottest card would probably work quite well. There wouldn't be much of an "air short circuit" from the warm exhaust being sucked back into the intake.

(You could avoid that problem entirely with a bit of cardboard ductwork, or a snazzy plastic version.)

I'd go for a slot fan that sucks air in on both sides. The two-slot-wide Thermaltake TMG SL1 would suit, and isn't outrageously expensive for what you get; Aus PC Market stock it for $AU40.70 including delivery (Australian shoppers can click here to order one!).

If you've only got a one-slot gap, there's a smaller Thermaltake fan, the A2426, that doesn't look too bad. Aus PC Market stock that one for $AU20.90 delivered (and Aussies can click here to order it).

You could also, of course, bodge in any old computer fan you have lying around, using tape and Blu Tack.

As I mentioned above, my main PC's motherboard has been cooled by a Blu-Tack-based system for ages, now.

(If it's stupid but it works, it ain't stupid.)