Heat of a PSU

[mattg1981]

Does the larger a PSU gets (ie ... 450 -> 400 -> 420) ... does it start to produce more and more heat?

I am pretty sure that just logics would tell you yes .. but I have a new system and running this badboy seriously makes my whole room hot ... and the most heat is coming out of my Enlight 420 W PSU.

If I switched over to an Antec 450 ... would it run any cooler? Which is the 'coolest' running PSU over 420 W? I ran GooPSUlator and it says I need at least 419 W. Any way too cool my PSU down, or do all PSU's over 400W run hot?

 

[Regs]

Edit*

Sorry, mis replied.

 

[mattg1981]

awww, you had me all exicited that someone answered my question 🙁

 

[ElFenix]

i went from an antec 300 to an antec 330 an i swear its a bit warmer.

you don't need 400 watts would be my advice

 

[Alkali]

My 520Watt PSU runs really nice and warm, but never hot. Then again it has 3 fans and is aluminium so... 😛

 

[Macro2]

Dang right it does. On top of that some PSes are just plain hotter than others at the same wattage rating..
No one seem to realize how much PSs can heat up your case temps.

 

[mattg1981]

so which brand makes the coolest running PSs?

 

[ElFenix]

maybe vantec? although really theres only, say, 4 or 5 companies that make the internals so many PSes are going to output the same amount of heat. one thats better ventilated might run "cooler" but its still heating up your room just the same.

 

[Auric]

It's prolly the new system drawing more power that is making the PSU produce more heat, not because the PSU is capable of outputting more power. Remember it will only output as much as is required, not necessarily its max. If you want a more efficient (and thus cooler and quieter and less costly to run, plus no EMI or RFI) then get one with Active PFC. That rules out Antec brand outside the EU.

 

[boyz]

not really unless your psu is working to the max, i had a 250 w generic psu and then i bought a 350 enermax ultra quiet and i didn't notice any difference but the noise level dropped.

 

[Mark R]

Heat generation in the PSU is related to the load that they are supplying - if they are working harder then they will get hotter. Most PC PSUs are about 70% efficient at normal load. This is not significantly different between different models and different brands - essentially because they all use extremely similar designs. A higher rated PSU may use more power for some components (higher rated switching transistors), but at the same time, other components may use less (higher rated rectifier diodes).

For a fully loaded (1 CPU) PC, which might need as much as 150W of low-voltage power, the PSU might be need 65W for itself - In other words, the PSU would be generating nearly as much heat as a 3 GHz CPU.

Another note: Active/Passive PFC does not change efficiency much (it certainly doesn't improve it, and may worsen it slightly), and therefore does not change running costs. All it does is make the PSU more 'power company friendly'.

 

[Auric]

Originally posted by: Mark R

Another note: Active/Passive PFC does not change efficiency much (it certainly doesn't improve it, and may worsen it slightly), and therefore does not change running costs. All it does is make the PSU more 'power company friendly'.

Bzzzt!

Next?

 

[Mark R]

No offense, but power factor and efficiency are totally seperate entities.

In a PSU the ineffeciency comes from energy loss in the various components. By *adding* a further stage (in active PFC the active PFC module is in fact a complete, but simple, switching power-supply) the losses are not reduced.

Say, you have a PC with a non-PFC PSU, the PSU may be drawing 200 W from the mains, but be taking 3A @ 110V. Replacing the PSU with one with active PFC, you would still need 200 W from the mains, but the current may be reduced to less than 2A.

As your electricity meter only measures true energy delivered, it will increment at the same rate with both supplies. However, running 5 of the first systems would come dangerously close to blowing a 16A breaker, whereas you could probably run 7 of the latter type from the same circuit.