PSU questions

Cavallino · 10 Dec 2009 at 00:00

I recently got a Corsair 750HX.
Its a nice Power supply, but I was just wondering, when I play games such as MW2, it spins up a fair bit that I can hear it.
Whereas when I dont play any games, its quiet.
Is there anything I can do to make the fan in the PSU not spin up?

Are Corsairs supposed to have quiet fans in them when spun up? Or is there quieter PSUs available? (Presumably some fans are load based and others temperature based?)

I guess what I want to arrive at, will I find a fan that is quieter than the one I have at the moment.

Cheers in advance

fornowagain · 10 Dec 2009 at 00:08

Not much you can do about that tbh, and I wouldn't recommend going in a psu unless you know what you're doing. They can hold a dangerous charge for quite awhile. The fan is controlled by the internal temperature of the psu, so obviously speeds up when its getting used and producing more heat.

Cavallino · 10 Dec 2009 at 08:07

fornowagain said:
Not much you can do about that tbh, and I wouldn't recommend going in a psu unless you know what you're doing. They can hold a dangerous charge for quite awhile. The fan is controlled by the internal temperature of the psu, so obviously speeds up when its getting used and producing more heat.

But is the fan speed dictated by temperature! or by system load!
I dont think its both. Can anyone clarify?

How does your PSU sound fornowagain? Does it spin up under high load that you can hear it?

Are there more silent alternatives than the Corsair HX750?

sastusbulbas · 10 Dec 2009 at 08:14

Are you sure it is not your graphics card?

What you are describing sounds like what I experience with my 4870 card, regardless of it being my Hiper, Corsair or Seasonic PSU.

fornowagain · 10 Dec 2009 at 14:36

Cavallino said:
But is the fan speed dictated by temperature! or by system load!
I dont think its both. Can anyone clarify?

How does your PSU sound fornowagain? Does it spin up under high load that you can hear it?

Are there more silent alternatives than the Corsair HX750?

Its determined by the temperature inside the psu case. Which increases WITH load, but its temperature dependant. Mine is a PSP&C and is quite loud to start with but doesn't seem to get any louder, amazing psu but not the quietest.

Cavallino · 10 Dec 2009 at 17:08

sastusbulbas said:
Are you sure it is not your graphics card?

What you are describing sounds like what I experience with my 4870 card, regardless of it being my Hiper, Corsair or Seasonic PSU.

Positive. I manually turned set the fans on the 5770s to a minimum. And I tbh, at full speed the 5770 fans are a differen noise compared to what I am hearing. I am 99.9% certain its the PSU fan.
But interesting you mention the seasonic as I had an S12 previously and it did the same thing, albeit the fan was probably a bit louder on the seasonic compared to this Corsair... which probably ties in what fornowagain is saying.

fornowagain - I was told that some PSUs only spin up when the ambient temperature inside the psu gets high while others spin up as more current is drawn.
(I understand that higher current causes higher temperatures but perhaps there are PSUs that independently work on this premise?)

fornowagain · 10 Dec 2009 at 18:58

I've not seen one yet, they generally use a thermistor to monitor temperatures. Simple straight forward circuit. Monitoring load current to control fan speeds would be counter productive as it takes no account of ambient temperatures and quite complex to implement although not impossible. They aim to stay below or at a setpoint within the psu case, depending on manufacturer 40C & 50C are common values. Of course the design and proximity of the temperature monitoring can effect how rapidly it responds to changes in heat from load current.

Cavallino · 10 Dec 2009 at 19:49

fornowagain said:
I've not seen one yet, they generally use a thermistor to monitor temperatures. Simple straight forward circuit. Monitoring load current to control fan speeds would be counter productive as it takes no account of ambient temperatures and quite complex to implement although not impossible. They aim to stay below or at a setpoint within the psu case, depending on manufacturer 40C & 50C are common values. Of course the design and proximity of the temperature monitoring can effect how rapidly it responds to changes in heat from load current.

Ok many thanks fna. I got some new Noctua case fans so perhaps they make a difference... lets see