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PSU PSU location.

Discussion in 'Hardware' started by Corky42, 6 Dec 2018 at 17:38.

  1. Corky42

    Corky42 What did walle eat for breakfast?

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    I'll get straight to the point, why do case manufactures still try to isolate the power supply?

    I think i understand why it started to become a trend but with improvements in the control we have over the rest of a cases fans and most PSU's being pretty quiet these day why's there still a need for separate PSU compartment.

    Isn't the standard ATX layout with the PSU at the top helping with exhausting warm air better these days, am i missing something?
     
  2. Sentinel-R1

    Sentinel-R1 Morse Monkey

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    PSUs are far more efficient than they were when the ATX standard was first set. Back then, they probably gave off more heat than the CPUs did (my first 486 was a naked chip - no heatsink!) and discrete graphics cards weren't really a common thing - so it made sense to put them at the top.

    Nowadays, with the exception of HDD/SSDs, they're one of the coolest things in a PC so leaving the upper part of the case clear to exhaust heat from CPU/GPU makes more sense.

    Moreover, unless you have a 'pretty' PSU and nice braided cables, its a lot more desirable to hide the unsightly ketchup and mustard spare cables out of sight with a shroud.
     
  3. Anfield

    Anfield Well-Known Member

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    Even if braided they still need hiding because they will be far too long unless you buy some super huge case like the Corsair 1000D.
     
  4. Sentinel-R1

    Sentinel-R1 Morse Monkey

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    In which case, if you did buy a super huge case, you end up having to purchase an 8Pin & 24Pin extension cable! Can't win either way!
     
  5. CrapBag

    CrapBag Well-Known Member

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    It's more to do with hiding the cables than anything to do with thermals in my eyes.

    I'd love a case that hides the PSU as I hate cabling, plus all our pcs have the PSU at the bottom where they should have been in the first place for me.
     
  6. Sentinel-R1

    Sentinel-R1 Morse Monkey

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    I don't know so much. They've been at the bottom of cases for years and years before shrouds came along. Cables weren't hidden then.
     
  7. CrapBag

    CrapBag Well-Known Member

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    Yeh PSUs have been at the bottom for ages but shrouds are fairly recent, but that's what I'd like, if I had the equipment here I'd make shrouds myself.
     
  8. Corky42

    Corky42 What did walle eat for breakfast?

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    Yea i totally get that and i think PSU's first started to be moved down as the thermal loads inside cases went up in order to prevent the PSU's internal fan ramping up, we didn't have much control over the other fans so they wouldn't automatically speed up like the PSU one would, and the fans they used were typically 90mm or less cheap'o screamers.

    The thing is hasn't that changed in recent years, like you say PSU's are among the coolest things nowadays and with better automatic fan control isn't it better to share the exhausting of heat between the PSU and another fan, i mean some cases put the PSU in a separate compartment at the bottom and then put a 120mm fan exactly where the PSU would be normally.

    I get the desire to hide the cables but surely that can be done via other means while actually putting the PSU's internal fan to better use than just cooling itself.
     
  9. Sentinel-R1

    Sentinel-R1 Morse Monkey

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    What's more efficient though? A fan at the top of the case exhausting straight through a grille OR a PSU fan (that often isn't running as it's linked to load, not heat), pulling hot gpu/cpu air past a load of capacitors, components and wires, forcing the air to turn 90 degrees and then out a much tighter mesh? I know what I'd rather have.
     
  10. Corky42

    Corky42 What did walle eat for breakfast?

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    Efficient as in electrical efficiency, or as in exhausting warm air betterl'y?

    Air wise it's obviously a straight up fan but wouldn't it need to be like two times better, at a guess it's maybe 10-20% less efficient to go through a PSU but the amount of extra space taken up from a separate PSU compartment seem disproportional to the increased efficiency.

    Don't get me wrong I'm not questioning anyone's personally choice, it's more about if separate PSU compartments are still technically better.
     
  11. Sentinel-R1

    Sentinel-R1 Morse Monkey

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    Exhausting the air, I meant - sorry for the confusion.

    I reckon you easily lose much more than 20% efficiency turning air through 90degrees, past a load of components and through a tighter mesh - plus as I said before, modern PSU fans are linked to PSU load, not heat, so often don't run until high power draw meaning it's doing nothing the rest of the time.
     
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  12. adidan

    adidan Avatar is in season. See it while stocks last.

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    Many PSUs run their fans extremely slowly or turn them off if necessary.

    No point making them work pumping out hot air from elsewhere in the case when a low powered fan can do the job.
     
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  13. Corky42

    Corky42 What did walle eat for breakfast?

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    I know some are but i thought the higher quality ones had moved over to linking fan speed with temperature instead of load.
    Isn't it better for them to be doing something rather than nothing, or at least next to nothing, though.

    I mean I've got a case with an isolated PSU compartment and its fan is basically wasted while the fan in the compartment where the rest of the comments are has to spin twice as fast, wouldn't it be better if the main rear fan only had to spin at 50-75% because the other 25-50% exited via what use to be an underutilised fan.

    Like i said it used to make more sense to have the PSU in it's own compartment when we all used HDD, we didn't have sophisticated fan control, heat from components were overwhelming the PSU, PSU's were lower quality and we had room to spare.

    It seems most of the reasons for having a separate PSU compartments in the first place has largely been address but case manufactures still seem wedded to the idea of using up massive amounts of space in their cases to house nothing more than the PSU.
     
    Last edited: 7 Dec 2018 at 00:00
  14. wolfticket

    wolfticket Downwind from the bloodhounds

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    I think part of the reason is that the PSU is generally the only actively cooled device in the system that has relatively unsophisticated discrete fan control that is controlled independently of the rest of the system. This combined with a naturally congested airflow within the PSU means that it is well suited to cooling itself in isolation and less suited to acting part of the wider airflow of within the system.

    Dropping and isolating the PSU at the bottom of the case and effectively replacing it with a system controlled upper fan is a better solution overall. I also think another reason PSUs used to be one of the noisiest parts of a system (other than obvious improvements in efficiency) that they were commonly treated as a auxiliary exhaust fan for the system, meaning already hot components within the PSU were being cooled with warm congested air.
     
  15. adidan

    adidan Avatar is in season. See it while stocks last.

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    Oh I agree to an extent some cases are just pants.

    My mATX case is ideal for me though, bottom compartment fits the PSU and cables without room for anything else other than a couple of SSDs.

    But yeah that's mATX not ATX.
     
  16. Corky42

    Corky42 What did walle eat for breakfast?

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    Yea for a case like the ISK-600M it makes much more sense, i guess I've become a little jaded having spent the last 3 days looking at cases with 51/4 inch bays and PSU compartments that just seem to be wasted space. :(
     

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