Overheating Problem

[Limber]

Hi everyone, I've got a nasty overheating problem with my computer, and need a bit of advice. I'm looking for a way to increase the exhaust airflow of a Seasonic X-650. I've explained my situation in more detail below for those interested, but you can skip to the end if you want to get to my questions.

I have an Antec Solo case with a mid-range GPU and a full compliment of hard drives. I recently donated my former power supply to my parents' new computer, and purchased the Seasonic X-650 while it was on sale as replacement. I failed to consider the thermal consequences.

Unlike my previous power supply whose fan was always spinning, the Seasonic's fan never kicks in since my computer isn't very power-hungry. The case's rear exhaust fan is actually pulling warm air down from the X-650 into the case, exhausting it, and pulling it back in through the power supply again in a pointless closed loop (tissue paper "sticks" to the grill of the power supply). There is virtually no fresh air flowing into the front of the case anymore. Out of curiousity, I briefly duct-taped the X-650's fan grill to see what would happen, and fresh air started flowing into the front again.

Anyway, with the case buttoned up, all of the major components (CPU, GPU, hard drives) are 10-20°C hotter than they used to be, with the hard drives suffering the most. I blew it. For the moment, I'm forced to run the computer with the side panel removed to protect the equipment inside.

Questions:

a) I'm thinking about plugging in the power supply's fan externally, either to a motherboard header or a molex connector (possibly replacing the fan if necessary). If I do, will the power supply still function properly, even though a fan is no longer plugged into its circuit board? (I realize I'd be voiding the warranty, and I'd probably have to do a bit of damage to the power supply's casing to re-route cables.)

b) This is a long-shot, but it can't hurt to ask... can the existing fan's behaviour be modified so that it's always running?

I've also been looking at new cases (Fractal Design's R2 looks nice), but money's tight right now, so modifying the X-650's fan appears to be the most economical approach for now.

[Zero82z]

Are you using your rear fan as an intake? If so, reverse it. That fan should be an exhaust. Which Solo case do you have? You probably have room for an intake fan in the front as well, so put one there if there isn't one already.

Now, on to your questions:

a) Don't.

b) No. The only way to make the fan spin would be to draw more power.

The fact is, your case airflow should not be dependent upon the PSU at all. If yours is, then you do not have your fans arranged properly. If you provide more details about your specific case and how you have fans positioned, I can give you suggestions for improving the situation.

[Limber]

Thanks for the quick response.
This is my case (the Antec SOLO): http://www.antec.com/Believe_it/product.php?id=MTk
The rear fan is an exhaust, a Scythe S-Flex, which spins at either 800RPM or 1200RPM.
Unfortunately, when mounting 3 hard drives using the elastic suspension provided by Antec, there isn't enough room to install front intake fans. It's just too damned tight, given all the cables and the video card in the way. However, you've given me an idea... maybe I can whip up my own hard drive suspension system, which could possibly yield enough room for intake fans up front. I'll look into it.

Originally Posted by Zero82z

The fact is, your case airflow should not be dependent upon the PSU at all.

If my observations are valid though, then in a traditional case where the power supply is directly above the rear exhaust fan, it matters a lot. If the power supply's fan isn't spinning, then it's essentially just another opening in the computer case, and there's nothing to stop the exhaust fan from pulling heated air down into the case and exhausting it again, repeatedly. It no longer needs to pull nearly as much air from the front of the case, since it has the power supply feeding it right above, so the hard drives overheat. I believe that's what has happened here, and for a traditional case like mine, it's a pretty good argument for avoiding a power supply whose fan doesn't spin at lower power draws (like Seasonic's X-series).

2 Years ago, I removed the fan of my previous power supply, an Enermax Pro 82+ 385 watt. It was too noisy due to bad bearings. I put an Antec Tri-Cool in its place, dremelled a small hole in the power supply cover to feed cables through, and hooked up the fan externally to a molex connector. It's worked perfectly since then (better cooling too). Basically I was thinking of doing the same sort of thing with the X-650, albiet with a nicer fan this time. Therefore, my goal here is to determine whether ot not the X-650 will continue to function properly without a fan plugged into its circuit board (but still being cooled by an externally connected fan). If you guys say it won't, then I won't do it, end of story.

To be honest though, that Fractal Design R2 is looking better and better. I really don't want to void the warranty or cut a hole in my new power supply, dammit.

[blivit4]

Yes, in your case, because there is less impedance between the rear opening for the PS and the case exhaust fan, than there is between the front of the case and the rear fan, the flow short circuits through the PS.

You need to either get more air flowing out of the rear case opening (make sure your S flex is the 1200 RPM one), or you'll have to find a way to make use of one of those 92mm front fan mounts and mount a fan. You might be able to mount a 120mm fan behind the HD drives inside the case.

[Zero82z]

Originally Posted by Limber

If my observations are valid though, then in a traditional case where the power supply is directly above the rear exhaust fan, it matters a lot. If the power supply's fan isn't spinning, then it's essentially just another opening in the computer case, and there's nothing to stop the exhaust fan from pulling heated air down into the case and exhausting it again, repeatedly. It no longer needs to pull nearly as much air from the front of the case, since it has the power supply feeding it right above, so the hard drives overheat. I believe that's what has happened here, and for a traditional case like mine, it's a pretty good argument for avoiding a power supply whose fan doesn't spin at lower power draws (like Seasonic's X-series).

You're missing my point. The PSU is not supposed to be responsible for cooling off the PC. Its fan is there only to cool down the PSU itself. The rest of the components should be cooled down by the case fans. If your PSU is making a big difference to your cooling, then your case cooling is inadequate. That's what you need to deal with, not the PSU.

[Limber]

Naw, I get your point, Zero, and I absolutely agree with you, the PSU shouldn't be responsible for cooling beyond itself. I just don't think the Antec Solo epitomizes that design philosophy very well, which is why I've run into difficulties. Even with the rear fan zipping away at 1200rpm (noisy), the hard drives are baking at 50°C. In hindsight, having an active fan in my former power supply must have helped compensate for my case's weak cooling.

Anyway, you guys are right, the cooling's inadequate... I'll find a way to test out a 120mm fan in front, and if that doesn't cut it, I'll throw in the towel and purchase a new case. I'm not going to mess with the power supply after all.

Thanks