Simpleton low noise power supply

[Andrew Diamond]

Took a random power supply, replaced its 80 mm fan (the standard apparently)
with a SilenX 14db one I had laying around (about $10-$15), routed the fan's
3 pin cable through the same hole in the power supply as the other wires,
attached that to a zalman $5 fan-mate speed control and, after futzing
around to guage sound and temperature, set the fan to spin about about 1600
RPM. Oh, I also bothered to use the SilenX rubber connectors (I don't know
if they helped but they couldn't hurt).

I see no increase in temperature and its pretty damn silent. The power
supply was a freebie with a case as I recall. I've run the machine at 100%
CPU utilization for half hr and it the temperature and stability seem fine.

It's been my subjective and unquantified observation that except for chip
cooling, you can use a very slow low performance fan and achieve silence
with little heat detriment.

Obviously, if you're an overclocker things will be different though I've
also reduced the speed and noise of my Thermaltake Silent Boost cooler's CPU
fan to 1900RPM and that's worked just fine too.

 

[kony]

Took a random power supply, replaced its 80 mm fan (the standard apparently)
with a SilenX 14db one I had laying around (about $10-$15), routed the fan's
3 pin cable through the same hole in the power supply as the other wires,
attached that to a zalman $5 fan-mate speed control and, after futzing
around to guage sound and temperature, set the fan to spin about about 1600
RPM. Oh, I also bothered to use the SilenX rubber connectors (I don't know
if they helped but they couldn't hurt).

I see no increase in temperature and its pretty damn silent. The power
supply was a freebie with a case as I recall. I've run the machine at 100%
CPU utilization for half hr and it the temperature and stability seem fine.

It's been my subjective and unquantified observation that except for chip
cooling, you can use a very slow low performance fan and achieve silence
with little heat detriment.

Obviously, if you're an overclocker things will be different though I've
also reduced the speed and noise of my Thermaltake Silent Boost cooler's CPU
fan to 1900RPM and that's worked just fine too.

Whether you can swap a fan depends quite a bit on how much power the unit
is converting, therefore the amount of heat inside, needing removed. Also
if PSU isn't being relied on to cool rest of chassis then it can also have
lower flow rate.

You didn't need to go to the trouble and expense though, typical fan
replacement would be any of the more common "low" speed fans with average
cost online of $3-6 (not a cheap generic sleeve-bearing fan!) and wire to
original fan header or splice to wires if they're soldered to PCB. No fan
controller needed.

On the other hand, typically the time spend customizing a power supply is
best spent on a good unit with ample reserve, something that will last a
long time, rather than a generic came-with-case type. Your fan and speed
controller are probably worth more than the whole power supply.

 

[Andrew Diamond]

Whether you can swap a fan depends quite a bit on how much power the unit
is converting, therefore the amount of heat inside, needing removed. Also
if PSU isn't being relied on to cool rest of chassis then it can also have
lower flow rate.

You didn't need to go to the trouble and expense though, typical fan
replacement would be any of the more common "low" speed fans with average
cost online of $3-6 (not a cheap generic sleeve-bearing fan!) and wire to
original fan header or splice to wires if they're soldered to PCB. No fan
controller needed.

On the other hand, typically the time spend customizing a power supply is
best spent on a good unit with ample reserve, something that will last a
long time, rather than a generic came-with-case type. Your fan and speed
controller are probably worth more than the whole power supply.

I haven't seen any other 80mm fans as quite as the SilenX ones. I happen to
have extra 14db ones around but they do make a 9db one and if I had had one
of those then perhaps I wouldn't have used the Zalman fan speed controller.
If you have a reference to a site the sells $3-6 super low noise 80mm fans
I'd appreciate it. I've never come across fans quieter than these. I also
happen to have about 5 extra power supplies running around that have done a
fine job but they're just too loud. I've never had a power supply die on
me, just the fans in the cheap ones. I used to be more wary of the cheaper
power supplies in the older Athlon systems but that doesn't seem to be the
case anymore. If I went out and bought a new extra low noise power suppy,
e.g. the Zalman, of which I have one, or the even quieter fanless ones, I'd
have to spend $100.

If I didn't have these other power supplies around or/and if they were
troublesome (perhaps if I had my computer loaded up to the gills with
stuff?) perhaps I'd do something different. In some sense I guess the fan
controller is worth more than the power supply given that I paid $5 for the
controller and the power supply came free with a case but then that's really
an artifcat of retail vs OEM bundling, etc. In the end, the question is
what it would cost me given what I have and, of course, whether its
sufficient to get the job done. Given what I've said previously, I think
the mod was worth it but I'd certainly be game to get find a source for
super cheap & quite low speed 80mm fans to bring down the cost of the whole
mod from $15 to $6 dollars. This is particularly true because as I said in
my previous post there seems to be lots of uses for such fans because other
than direct chip cooling, versus enclosure cooling, it seems to me that
unless your overclocking a weak fan doesn't seem to yield much higher
tempatures than a strong one. That was a surprise to me but I've measured
such temperatures time and again and I never see the large difference you'd
expect (or at least the horrible heat you'd expect from the weak fans).
Even when I was running the machine hard; if I had turned the case fans off
the computer heated up like crazy. Turning on a fan blowing into the
motherboard from the side was the most effective cooling. Having another
one blowing out the back was next. It didn't make much difference whether I
ran those fans at full speed or minimum speed. Perhaps if my room
temperature was cooler it would have but, well, it's not.