[mythtv-users] Re: Quiet Power Supplies/Quiet PC's

[Jeff Williams]

As I've had power supply issues on various PC's over the years, let me try to answer this...

I said before that the quietest PSU I've owned is my current, cheap, $18 Allied model.  That's true.  And I've been happy with the results from it and have never had a crash.

I've also bought expensive PSU's that have turned out to be basically trash.  I'm currently wrestling with a $70 Enermax 350 watt PSU in my gaming PC that I'm convinced is responsible for basically killing my PC over the past couple of months.  The PC itself is now pretty much completely dead and I am currently in the process of replacing the CPU and power supply (CPU was giving me problems and I RMA'd it, but I now suspect it was really the power supply all along)... hopefully that will fix it, but it's possible I now also have a dead motherboard (no beeps at all on boot).

This happened over a period of time, and like you said, it was probably due to increasing demands on the power supply as I upgraded my CPU, graphics card, motherboard, and memory, added 5 new fans and a fan controller/LCD display.  I also believe this is why cheap PSU's "die" after a while - but expensive ones can die too if you overload them.  The problem with my Enermax "350 watt" model is that it only offers up a maximum of 185 watts on the most important 3.3v and 5v rails, which are clearly overloaded at this point, or at least right on the edge of being overloaded.  Booting is the most stressful thing a PC can do and my PC just won't boot.

By comparison, my cheap Allied 300 watt unit in my HTPC offers up 180 watts on those same rails.  But I'm running far less powerful equipment in that PC, and I paid 1/4 the amount of money for this power supply as for the Enermax for basically the same level of performance.  I've had no issues at all with the Allied unit running this low-power equipment.

I'm replacing my Enermax with a 400 watt Antec model that's rated at 230 watts on the 3.3 and 5v rails.  That should be enough for that PC.  180 watts on those rails is clearly enough for my HTPC right now, but may not be as I upgrade the PC with hand-me-downs from my main PC over the next few years.  I don't think PSU's die over time, I think they become overloaded as you add things to your PC, and most people don't bother paying attention to a PSU until they start having problems.

Oh, one other spec to pay attention to is ripple - you want a good, consistent current going into your PC.  I'm actually not sure how cheap PSU's like my Allied compare in this area, but again, this is not a spec that should change over time.

It doesn't matter how much you pay for a PSU.  What the expensive models do usually give you are bigger heatsinks, better construction and better fans rated for longer hours of use (for example, my Enermax PSU has ball-bearing fans rated for 100,000 hours, while my Allied unit has a sleeve-bearing fan rated for 50,000 hours).  But as long as you look at their power ratings carefully, you can get a decent PSU for pretty cheap... though there's still a threshold below which I wouldn't go, where things do start to get really dodgy and you can actually get a PSU that physically falls apart in a slight breeze.  I actually meant for this Allied PSU to be temporary and it probably still will be, but I've been pleased at how well it's done so far.  I'd still probably recommend spending more for something like an Antec if you can afford it, just because then you don't even really need to worry about looking at the specs, you can pretty much assume they're good.

> -----Original Message-----
> From: Ray Olszewski [mailto:ray at comarre.com]
> Sent: Thursday, July 10, 2003 12:35 PM
> To: mythtv-users at snowman.net
> Subject: Re: [mythtv-users] Re: Quiet Power Supplies/Quiet PC's
> 
> 
> At 09:07 PM 7/9/2003 -0400, Mark wrote:
> >When I made that statement, failure implied a failing 
> system.  While the 
> >cheap power supply keeps
> >producing power, it's simply not stable.  Wierd crashes 
> become common, 
> >even in Linux.  Replace power
> >supply, problems go away.  Seen it way too many times.  I've 
> got a stack 
> >of power supplies in my
> >cabinet that still power up, but aren't stable.  My good 
> power supplies 
> >don't do that.  I'm sorry your
> >expensive 1U supplies died, but it's not been my experience.  YMMV.
> 
> As you say, "[M]MMV". That's very different from "Cheap power 
> supplies 
> ALWAYS die after about a year or two". I don't doubt your personal 
> experience, only the generalization you make from it.
> 
> And surely "die" means something more drastic than "still 
> power up, but 
> aren't stable", at least the way I usually use words.
> 
> But my real interest in responding is to explore the details 
> of your actual 
> experience a bit more, now that I understand a little more 
> about what you 
> are really observing. I too have had what I would call 
> stability problems 
> (most commonly spontaneous reboots) with some of my cheap 
> power supplies. 
> Replacing the power supply always (actually only 2 or 3 
> instances over the 
> last 5 years) fixed it.
> 
> But I always replaced the "unstable" power supply with 
> another cheap one 
> that had higher wattage. So I inferred from this that what I 
> was actually 
> seeing was transient power demands that exceeded the capacity 
> of the P/S, 
> rather than a "cheapness" problem per se (except that higher 
> wattage power 
> supplies generally cost more).
> 
> Does this sort of pattern at all match your actual observations (as 
> distinct from your interpretation of them)? My impression is 
> that people, 
> me included, tend to underestimate *transient* demands on 
> power supplies 
> very often, though they (we) usually get the steady-state 
> requirements 
> about right.
> 
> >Ray Olszewski wrote:
> >
> >>At 02:57 PM 7/9/2003 -0400, Shirley, Mark R wrote:
> >>
> >>>Cheap power supplies ALWAYS die after about a year or two.
> >>>I will never go back to cheap PSU's.  Pay $15-20, get one year.
> >>>Pay $40 or more, get 5-6 years.
> 
> [old stuff deleted]
> 
> 
> 
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