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PSU top or bottom?

Last response: in Components
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Which do you prefer?

Total: 29 votes (7 blank votes)

  • PSU at the top of case
  • 50 %
  • PSU at the bottom of the case
  • 46 %
  • other..
  • 5 %
October 31, 2008 6:50:40 PM

I've been looking for a new case recently and noticed alot of the cases i like have the psu at the bottom of the case for example: Antec 900. So is this something i should avoid? but alot of cases are like that so is it really a big deal or will i notice higher temps? any good and cool full tower case suggestions would be nice. thanks

More about : psu top bottom

October 31, 2008 7:15:39 PM

a good full tower case would be the antec 1200 ( the 900 is a mid tower) or the coolermaster 830. my personal fav would be the antec though.
a c 248 ) Power supply
October 31, 2008 8:04:41 PM

There is no need to avoid a bottom mounted psu.

The only minor problem might be with full tower cases and motherboards with the 6 pin, 2x3, ATX power connection located at the very top of the motherboard. Some people reported that their 6 pin power cables couldn't reach the connection at the top. The problem is very easily solved with an 8 inch extension cable available at many online vendors. That's what I did.

I have the CoolerMaster 932 HAF case and a Corsair power supply. I mounted the psu in the bottom of the case with the psu fan facing down. There is perforated mesh/grill directly below the psu fan. The fan sucks in cool air from the bottom and exhausts warm air out the back. The psu cools itself while other fans located elsewhere cool other components.
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October 31, 2008 8:07:04 PM

There's no disadvantages to a bottom-mounted PS. Like JohnnyLucky said, just make sure your ATX line can reach the ATX connector on the motherboard.
October 31, 2008 8:41:39 PM

ilovebarny said:
a good full tower case would be the antec 1200 ( the 900 is a mid tower) or the coolermaster 830. my personal fav would be the antec though.

Yea i just used the 900 as an example bc i figured alot off ppl kno what a 900 looks like
October 31, 2008 8:57:56 PM

ya a lot of people do know what it looks like, and its big for a mid tower case too.
November 1, 2008 7:05:11 AM

drip50291 said:
I've been looking for a new case recently and noticed alot of the cases i like have the psu at the bottom of the case for example: Antec 900. So is this something i should avoid? but alot of cases are like that so is it really a big deal or will i notice higher temps? any good and cool full tower case suggestions would be nice. thanks


Personally, I prefer a top-mounted PSU. Thermal convection will naturally take hot air to the top of the case, and the PSU's fan will help remove that. (I measured internal temps on my PSU and found at most a 2c difference between top mounted and running outside the case) That said, if you have the room for a full tower or a very large mid tower, and it has an intake for room temp air to used, overall it should make little difference. Make yourself happy with whatever case you like, just make sure (as already mentioned) that your PSU's various connectors will reach, or that you have a ready source for extensions.
November 1, 2008 7:23:14 AM

The PSU on the bottom makes for easy cable management.
November 1, 2008 7:43:28 AM

I'd say the bottom, but then again all depends on the case
a b ) Power supply
November 1, 2008 4:53:58 PM

Had to vote - Top.
Just swapped a Theraltake Swing for a Coolermaster 690. Everything else being equal, Same hardware including fans, the system ran cooler in the Top mounted. primarily NB is about 4 -> 6 C higher.

I prfered the cable management whit the top mounted position. I could tuck the 24 pin and 8 pin Power cable to MB at top of case vs running them up inbetween the HDD cage and MB which I think restricks some of my air flow front to back.
November 1, 2008 5:00:37 PM

JohnnyLucky said:
There is no need to avoid a bottom mounted psu.

The only minor problem might be with full tower cases and motherboards with the 6 pin, 2x3, ATX power connection located at the very top of the motherboard. Some people reported that their 6 pin power cables couldn't reach the connection at the top. The problem is very easily solved with an 8 inch extension cable available at many online vendors. That's what I did.

I have the CoolerMaster 932 HAF case and a Corsair power supply. I mounted the psu in the bottom of the case with the psu fan facing down. There is perforated mesh/grill directly below the psu fan. The fan sucks in cool air from the bottom and exhausts warm air out the back. The psu cools itself while other fans located elsewhere cool other components.


I'm kinda in the same boat actually so glad to see this post, maybe someone with a similar rig would be able to confirm. I ordered a Corsair 750tx and an ANTEC 1200 for my CF setup 'cause I needed the extra room. BUT I didn't order the extender for the 8 pin CPU cable and I'm hopin' it won't come back to bite me in the butt. (Find out Monday)
a c 248 ) Power supply
November 1, 2008 5:14:56 PM

bosshoss - It's probably going to depend on the location of the 8 pin connection on your motherboard. I've seen a few odd locations. Luckily the extension cables are cheap. Unless you are near a Fry's Electronics or Microcenter store, the cheapest shipping will cost you more than the cable.
November 3, 2008 6:40:04 AM

I'm an on-top kinda guy.

The (few) cases I've seen with the PSU on the bottom intake from a vent in the base of the case, ie outside air. I have three issues with this:

1) Its sucking dusty air up from a tight clearance area filled with carpet (if you have hardwood or laminate flooring this may be ok for you). I also don't think the PSU is going to get the breathing room it needs (just my opinion I haven't tested it) and the fan is going to have to work harder which will increase the noise.

2) Bringing air from outside the case directly into the PSU and venting directly out again takes the fan out of the case's air cooling equation. The PSU fan is no longer creating negative air pressure in the case to aid in airflow so you will need another exhaust fan to take its place.

3) As the PSU warms up the casing will contribute to the heat inside the case and do nothing to reduce it.

If you can mount the PSU "upside down" so it is drawing air from inside the case all of these issues would be addressed. However this also wouldn't be optimal as you are now drawing cooler air from the bottom of the case out and leaving warm air up top... you're still going to need that extra exhaust fan I mentioned in point 2.

Of course if you are one of those fan-nuts who has 10 fans in their case, points 1 and 2 are irrelevant.

Just me, I prefer fewer fans. Just 3. PSU with 120mm Fan up top and one other low-speed fan in the rear taking air out. A single 120mm up front sucking air in. Maybe an intake fan on the side over the CPU but its not necessary in my opinion.

my 2 cents
snazzed
a c 248 ) Power supply
November 3, 2008 10:08:41 AM

snazzed,

Most, but not all modern pc cases come equipped with added ventilation and several fans to improve air flow. As a result the bottom mounted psu's sucking in cool air from the outside are not an issue. In addition, with it's own cool air supply, the psu does not increase noise. Quite the opposite is true for psu's with temperature controlled fans.
November 3, 2008 3:36:06 PM

Hey JohnnyLucky

Yes, I am aware of the fact that most cases have increased ventilation and more fans, and actually mentioned it in my post and said if you have lots of fans, point 1 and 2 are void. I also mentioned that I like fewer fans.

I guess the best way to sum up my opinion is:

I don't think the PSU has adequate breathing room with a half inch clearance on the bottom of the case and breathing through carpet.

The cfm capacity of that nice 120mm fan in my high-end PSU is now "wasted" because its no longer interior facing.

Anyway, I don't think you're "wrong" here... and neither am I. Its an opinion.

At any rate, I'll likely end up going bottom mounted on my next build if only because all the cases I like (for other reasons) have bottom mount PSUs. I can't seem to find one I like with a top mount! :) 

Thanks
snazzed
a c 248 ) Power supply
November 3, 2008 5:44:09 PM

snazzed,

I lucked out on the carpet problem with bottom mount psu's. Long before I bought my first bottom mount case, I built a pc stand so I wouldn't have to reach down so far to get to a connection on the front panel. Back then manufacturers used to locate the USB and audio connections at the bottom of the case. PITA!
November 15, 2008 1:51:23 AM

the coolermaster HAF 932 comes with a power extension just for bottom mounting configuration, also if you dont like the bottom mount you can mount the PSU on the top with that case.
November 15, 2008 7:21:13 AM

Flip a coin, but bottom mounted can be a problem with short cables, which is easily addressed if needed.
!