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Fan and heat questions for a micro ATX

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January 26, 2008 1:00:48 PM

This is a homebuilt but it started as a HP. The only thing left HP is the Case and mobo. I am getting a new mobo and case next month, but i am having some heat issues due to the small case and the close vacinity of all the components and all those damn cables.

specs: Asus p5lp-le, pentium D 920 2.8G, 4G(2x2G) patriot pc2-6400, 250G SATA150 Seagate, dvd burner and CD-ROM, 500W antec basiq, turtle beach sound card, Sapphire ATI HD3870, 1 case fan exhaust, 1 case fan supply. Iits all jammed in there.

My northbridge is right up against the back of the 3870 and is directly beneath the GPU. The NB gets to hot to touch. It does have a heat sink but no fan. I am having some graphic issues but the 3870 seems to be ok, it never gets over 85c at load. But the back of the card and the NB get so hot. I suspect the few small issues i am having are, ambient + NB + 3870 = heat, related. The CPU seems ok, but my mobo doesnt have any cpu temp sensors so neither everest nor speedfan can read the cpu temp. the NB runs 60c'ish at load.

As i said, 1 supply 80mm fan(front), 1 exhaust 120mm fan(rear), a stock pentium fan, psu fan(exhaust) and the 3870 2 slot fan(exhaust). I have ordered a NB fan and round IDE cables to help.

here are my questions:

Should i change the air flow from supply front, exhaust rear to exhaust front, supply rear? The CPU is just beneath the rear exhaust, switching it would put fresh air directly over my CPU fan inlet.

Will the NB fan dissipate the heat between the NB and 3870?

If i had both case fans supply, is the 3870 fan enough to exhaust the rest? or is that a bad idea because it would flow hot air over my 3870?

Would a fan controller be a good idea to ramp up my fans while gaming? Rivatuner doesn't like some of my drivers. So if use rivatuner, i have issues.

remember in about 8 weeks i should be have the new mobo and full tower case all together, so i dont want to do to much.
a b B Homebuilt system
January 26, 2008 2:32:19 PM

Please tell us what base hp model you started with. You make it sound like you have a PSU in the front of the case?

I've worked on many HP computers and never seen this....

In general for HP cases you have air intakes on the power front and bottom of the case....and a rear fan and psu exhaust....

If you are worried about airflow increase the rear fan speed or replace it with a faster one(from what i have seen HP's default fan at full speed can move allot of air, but its loud...)...

Of you just want to mix the case air, you can get a fan holding bracket and put a fan to cool the chipset....Zalman has the FB123 that does just this... or you can also cut a hole in the side panel for a fan....
a b B Homebuilt system
January 26, 2008 3:04:55 PM

I would recommend keeping the intake in front and exhaust in rear, as this has time and again been shown to provide the best airflow in most cases.

It's hard to tell if the northbridge fan would help, I assume it would if you have the room for it. I have my 8800gt directly over my northbridge in my crosshair, I was scared because you could barely fit a matchbook between the two. However this has caused no issues and my northbridge idles at a normal (for me) 37C.

You didn't mention any fan sizes, would a 120mm fan fit? If you changed to a larger fan, that would increase all around airflow in the case. And I bet you would find a home for another 120 fan in your new case, when it arrives meaning it wouldn't be a wasted purchase.

An extensive article on cooling in CPU magazine recommends having an inequal case pressure to provide maximum cooling. For instance a 80mm fan in the front and a 120 in the rear, this would tend to "pull" more air through the case. This indicated it would also be effective to elimnate dead spot where hot air pockets form. This article indicated the opposite would work too, however looking at great cooling cases like the antec 900 (120 exhaust in back, 200mm blowhole on top) it looks like the extra pressure at the back and toop of the case is most effective.

A larger, high cfm fan in your exhaust would prolly be a minimal investment that would show an improvement that may hold off any more purchases for 2 months. I lkie the silenx 120 fans, but you can find a yate loon with a cfm rating of 45 for five bucks. They run nice and quiet too!
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January 26, 2008 7:03:15 PM

HP Pavillion a1000y. psu in typical spot, upper rear.

I have, 1 front supply 80mm fan, 1 rear exhaust 120mm fan. The rear exhaust fan never spins up. It stays a constant rpm. It barely blows. Don't forget the 3870's exhaust is external. The case panels are vented. In all i guess i have enough air in and out. I will add the NB fan and see how my temps react. If i need more i will replace the rear exhaust fan with a better one.
a b B Homebuilt system
January 27, 2008 12:41:29 AM

If the fan never speeds up, make sure Qfan is turned off in the bios. if its still not enough(if its on the fan will spin slow), replace the fan.

Are you sure its a 120mm? most HP's with that case use a 92mm fan.

If you want to attach a 40mm fan to the chipset you can do it with zip ties around the heat sink retention rods...or some times you can a fan into the heatsink it self(on most boards)
January 29, 2008 1:57:42 PM

My hp has an aweful bios. I havent seen anything in the bios like Qfan.

What about a fan controller? any good ones out? I would prefer analog with speed control only. So, when i am going to game, i can manually spin the case fans and the NB fan up. I have seen some around $40, but they are more than i need and they have bad reviews.
a b B Homebuilt system
January 29, 2008 6:33:11 PM

I thought you changed the HP board....

You can try to use speedfan to control it based on temps...

Post back if you need help with that....
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