As I shut down Winamp and sat back to relax a bit before heading to bed, I could just hear an odd low-frequency whine. Something new. Stuck my head under the desk by my main system, nothing but fan noise there. Move to the other side and get my ear close to my open-air footstool system, sounds like its coming from there somewhere.

Gently stop the Panaflos for the PSU and CPU and listen again. Still there, hard disk maybe? With the fans still stopped I pick the hard disk up and listen to it. Nope.

Wait a sec... I can hear it under the desk somewhere. Not the little backup server, its shut off at the moment. Under the desk I go.

Ah HAH! Found it.

My five year old APC battery backup unit was humming. Pushed gently on the side of it, shut up. Let go, hums again. Hrrrmm... Ended up laying on its side to stop its humming.


So nice that I've gotten everything to the point that its my battery backup making the noise that bothers me. Such a change from a few months ago when I ran my AMD system open-case on the desk RIGHT next to my left arm. Stock AMD cpu cooler, generic intake and exhaust fans spinning WAY too fast (and loud).

Yeah, this is good.


(edit add: ARGH! now I can hear a slight fuzz/buzz from my speakers. though thankfully MUCH less with the new Logitechs than the ancient Altecs)

and soon you'll hear your heart beating but hopefully you won't be so annoyed at that you'll set about trying to stop it...

and then the voices in your head... those voices... why won't they stop?

Actually, last night it was the grumbling of digestion that I wished would stop.

And this morning it was my neighbor's dogs again. <sigh>


I must have made progress though, got up this morning and had to check the LED on the computer to make sure it was on before I turned the monitor back on.

[quote="Zyzzyx"]My five year old APC battery backup unit was humming. Pushed gently on the side of it, shut up. Let go, hums again. Hrrrmm... Ended up laying on its side to stop its humming.[/quote]

actually, the reason I held off buying a UPS was that I was worried about the noise. currently, the only moving part of my PC is the HDD. can anyone recommend a cheap and silent UPS?

My experience has only been with APC and Belkin and the APC's, while definitely having a quiet hum are much, much quieter than the Belkin APC. I absolutely would not consider a Belkin APC for any of my systems.

I have two APC's in this room now.

VA500 is quieter
Smart UPS 700
note these numbers refer to "Volt-Amps". I have no idea why they chose these instead of wattage. I think it makes it look bigger.

UPS 700 has more features. It has a load meter, and other forms of feedback. it's also tons tons heavier. Think it has a cooling fan? the transformer noise when it recharges is much louder than the VA500. 500 Volt-amps comes out to around 350 watts?

On that note, I need a 1800 watt UPS for a ultrasound here at work. APC makes one that can handle it but it's well over 2000 bucks. ugh! they don't seem to make big ups's without all these fancy features that I won't use since it won't be hooked up to a computer. grumble!

APC Back-UPS 650 here. It is a completely silent unit, even when it recharges.

I think a computer's power use in volt-amps use will be greater than or equal to its power use in watts. The ratio of watts to volt-amps is equal to the power supply's power factor (PF). If the PSU has a PF of 1, the watts and volt-amps will be the same. As the PF decreases, the power demand in watts stays the same, but the volt-amps demand increases. Active power factor correction (Active PFC) PSU's can have a PF of up to 0.99 or so, while Passive PFC power supplies might have a PF of 0.65 or thereabouts. I guess this means that using an Active PFC power supply will improve the power-on time for a system running on batteries!

Okay, you may continue to talk about UPS's now.