PSU heat - safe or unsafe?

[david656]

Hi,

just got back from the computer fair with a new case and hdd for my home PC and whilst fitting it all in i decided to pop in a 400w PSU i had lying about that i recently changed the fan from the noisy stock one to a glowing orange silent one... as far as i rememeber they were litterally the same amps and voltage, but when i put my hand over the fan at the back heat is litterally pouring out of the thing.

How hot should a PSU get? should it feel so hot? is there anything i can do just to check its ok? I've just put my hand on another PC of similar spec PSU and you cannot really feel any heat atall just a slight very slight warm breeze.

cheers for any advise on this one

[TOK]

Sounds like the loud one was moving a lot more air than the pimp one.

[protokatie]

If they are the same wattage and/or you have no need for extra power, I would always go with the one that runs the coolest. A hot PSU will burn out faster regardless of how "pimp" it is. Also, depending on certain conditions, hot electronics do not conduct electricity in the same manor as cooler stuff, your overheated PSU may be giving out "dirty" electricity to the computer. This in turn can cause hotspots and can shorten the life of components. ("dirty" electricity would mean that for DC the voltage isn't constant, and for AC often means that the waveform isn't close to a sine wave. Either condition is bad news for electronics)
General rule with cars: Wider is better
General rule with electronics: Cooler is better

[SavannahLion]

Sounds like the loud one was moving a lot more air than the pimp one.

I'll echo that sentiment. The "pimp" ones almost never move anything even remotely the same volume of air as the "blah" ones. Many of them don't even cite CFM or anything rating remotely like it on their packaging. Adding spinning multi-colored lighting at the cost of half your air movement should go the way of the dodo.

Pay a few bucks for a better fan and pay close attention to that CFM rating.

[david656]

changed PSU back to the other 400w i had... and 'speedfan' recons this pc is like ideling at 57c ! apparently the AMD will like melt at 65c !

any idea's on what to do?

cheers again

[protokatie]

any idea's on what to do?

Nothing more to do. You fixed the potentially devastating problem. Bling is nice and all, but bling is worthless when your computer dies. Nothing like a piece of bling doorstop.
Functionality over superficiality when it comes to anything like this. If you wanted your computer to be "pimp" or "blinged out" you should have considered buying an Alienware computer or similar. Otherwise, just be like the rest of us boring-no-led-psu people.

Or did you mean that speedfan was telling you that the CPU was hot with the non-bling PSU? Regardless, AMDs tend to run hot (my laptop AMD hovers around 75C almost all the time). I do not even know if I trust most of the heat monitors out there. Regardless, the higher fan pcu is better than the bling one.

[Xiaou2]

 Todays trend for pcs is 'quiet'  technology.   They have intentionally produced many
fans to be as quiet as possible..   yet,  this more often that not comes at a cost
of moving a lot less air.

 The slower the airflow,  the more heat is going to build up.

 Look in to getting higher  CFM fans,   and a better CPU cooler unit.

 Also, if your pc is in a room that is very hot...  even the best fans may not be able
to help much.   In that event, try opening the side of the case and sticking one
of those huge box fans next to it.    If that wont do it... then you may want to refrain
running the pc until you get air conditioning... or simply do not turn it on scorching days.

 Heat shortens lifespan of components like the CPU.  It will also reduce harddrive life
too.  Ive noticed that many CPUs will slow down to a near crawl when they get too hot.


 Note - that Hard Drives create a lot of heat too.  So, place fans in front of them, so air
blows across their surface.   Try to have at least 1cm of space between each drive.
If poor circulation over hds, and more than one HD... the bottom drives heat tends to
rise up and Cook the top drive to an early death.

[MonMotha]

With power supplies, in general, the characteristic to buy on is, of all things, weight.  Heavier supplies usually have bigger heatsinks on their internal components.  This enables more effective heat transfer to the air which is flowing through them.  Experience suggests that you get what you pay for with PC power supplies.  The $30 "500W" power supply might put out 350W if you're lucky and it's running in a refrigerator.  The $150 "500W" power supply might actually be able to peak upwards of 600W and maintain regulation, ripple, and temperature if there aren't pre-set shutdowns lower.

...AMDs tend to run hot (my laptop AMD hovers around 75C almost all the time).

An old relic from the Athlon vs. PIII/early P4 days (who doesn't remember the Tom's Hardware video of the melting Athlon?).  AMD is actually a pretty leading entity in the "low power" market, now.  This was especially true when compared to the high-end P4s, and it's less true compared to Intel's newer stuff, but they don't "just run hot".  If your CPU is actually idling at 75C, then your cooling solution is broken.  75C is *really* hot.

Laptops often have poorly designed cooling.  They build them to look neat and be cheap.  My 2.4GHz P4m laptop readily overheats and downclocks when you look at it funny.  The heatsink and fan are just plain inadequate.  Do be sure that the heatsink is clear of dust and debris such as pet hair, though

Note that many temp sensors on PCs are uncalibrated.  They'll often read 30C high/low.  Not easy to calibrate, unfortunately, as the offset isn't always constant.