The Position of a PSU in a Case

PGdude · 30 Sep 2009 at 21:09

We all know that you can conventionally have the PSU at the top of the case, or less conventionally (But more frequently now) at the bottom of the case.

What is the point? What's the purpose of all of this? What are the advantages to either?

G-Dubs · 30 Sep 2009 at 21:19

perhaps the good lord can answer your question my child

Or to put it another way

God Knows

had you worried there didn't i??

niko · 30 Sep 2009 at 21:35

i like them at the top to act as a 2nd high level exhaust fan
some cases are easier to wire with the psu on the bottom and vice versa

beefybarn · 30 Sep 2009 at 21:50

I have always thought the idea of having them in the bottom is to allow a roof mounted fan to be fitted to extract the hot air that rises in a case.

SlugForAButt · 30 Sep 2009 at 21:51

G-Dubs said:
perhaps the good lord can answer your question my child

Or to put it another way

God Knows

had you worried there didn't i??

That's not very helpful but at least your post count is +1.

Back to the OP question, maybe it's to do with hot air rising from your PSU and getting exhausted.

PGdude · 1 Oct 2009 at 00:53

If the PSU is already exhausting warm air from itself at the top, doesn't it simply exhaust its own warm air and the system air with it?

Or is it because of the greater heat in the PSU itself causing the potential for convection to decrease, meaning the system as a whole stays warmer?

On the latter basis, I think I'll go for a PSU on the bottom case. Antec 300 has a fanon the top anyway, so... cool

jakspyder · 1 Oct 2009 at 02:14

i refer haveing the psu on the bottom the only slight problem is sometimes (certainly in my case) the 8pin mobo lead only jsut reaches the top of the motherboard and i imagine not every psu will have cables long enough

EsaT · 1 Oct 2009 at 09:27

niko said:
i like them at the top to act as a 2nd high level exhaust fan

PSU isn't exhaust!
Its high internal airflow impedance means its fan would have to run at lot higher speed than plain exhaust fan.
And compared to time when layout with PSU on top was designed now single freaking crappily engineered graphics card doing nothing can produce as much heat as whole computer (except PSU) then. And electrolyte capacitors which are one of the critical components (with temperature dependent life span) of PSU just happen to hate heat.

krooton · 1 Oct 2009 at 14:28

By having the PSU at the bottom of the case, you feed it cooler air, so it stays cooler, allowing slower fan speeds and prolonged lifespan.

dante6491 · 1 Oct 2009 at 14:56

Should also rattle less when it is at the bottom. Something to do with moments or whatnot.

reflux · 1 Oct 2009 at 14:58

Mine is sideways in the bottom of my case. I love Silverstones.

PGdude · 1 Oct 2009 at 19:51

dante6491 said:
Should also rattle less when it is at the bottom. Something to do with moments or whatnot.

I think I'll have to question my Physics teacher about this

I'm gonna dive into an Antec 300, because my StealthXStream is really quiet and cool, so I think it will be a great pair. Sounds good?

Ben Harrison · 1 Oct 2009 at 22:05

I guess a case with a heavy PSU would be more stable with it mounted at the bottom, too (though it's unlikely to matter).