Wirehead Studios

Today I decided to see if I could get better proformance from my PC. AMD 2700+, ati 9800 pro, gig of memory, 2x 80 gig drives  power supply=400w XP Pro...


I have never really changed any graphics settings, so I set the GL drivers to 'quality' rather than balanced, and that didn't improve my PFS in UT2004, that I could see, so I set it to 'proformance', and the game started as normal, then the screen went all choppy, and the motherboard stated saying something like 'ppd failure' over and over again, rather like a computer in ALIENS before the ship blows up, or something. there was also a burning smell. I could not understand what it was saying, but it kept restarting the comp over and over again....so i unplugged it.

tried taking the lid off the case, and the power suppy was really hot. really hot.  and then after it had cooled, managed to start and got into safe mode and did a sucsessful system restore.

QUESTION:  could it have been my fiddleing with the graphics settings that caused the powersupply to overheat? can this even happen? does a graphics card draw more power if you adjust the quality settings?

I type this on my old 800mgz P3 comp.  :huh:

Changing the graphics settings from "quality" to "performance" should not have caused a power supply overheat/failure.  "Performance" actually lowers visual quality to reduce load on the GPU, enabling it to render more frames per second.  Unless the card had a physical defect (eg, it had a short in it) the effective change in power demand should have been negligible.  I'd say you probably had a defective PSU and it just happened to fry at that moment.

I pulled a PSU out of a friend's system that had blown under similar circumstances a few months back.  It actually failed right under my beak as I was in the middle of doing a software repair on the OS.  It shorted out and suffered explosive thermal decoupling of two diodes.  It got hot enough to melt the solder points and literally blow them off the circuit board.  Nothing I was doing abnormally stressed the unit, it just happened to pop right at that time.

I think your PSU probably just chose your video tweak session as the opportune moment to fail.  Graphics cards do draw more power when in use in a 3D game than when idling on the desktop, but it sounds to me like it was already weak to begin with.  Usual causes of overheats are an overload, a short, excessive dust build up, excessive ambient air temperature, lack of proper case ventilation, or a failed exhaust fan on the PSU.  As for overloading the PSU, normally you'll notice system instabilities long before you cook one.  If you can rule out any of the other causes, then you had a defective unit and it almost certainly shorted out.  The other thing that will kill a PSU is a line voltage surge, like a lightning strike on the power grid.  It doesn't always happen at once either.  Like a static discharge, a surge from a distant lightning hit can stress the components without actually destroying them.  They'll fail later on.

Either way I'd say it's time to replace the PSU.  Hopefully it's not caused any secondary component damage on the way out.  Sometimes they do, sometimes they don't.  There's no way to tell without knowing exactly how the unit failed.

everything seems to be running ok again now, but i intend to replace the PSU tomorrow. maplins has a 600watt job that looks ok, and I can get it on the way home. I had only cleaned the dust out of the PC on sunday morning, and the fan seems to be working, so it must have just decided it had had enough.

Maybe I was drawing too much juce from the USB ports - but in fact each has its own powersupply, external HD, printer, and digital tv box, with only the external HD actually on at the time.


Compleatly unrelated question Pho- how much better is a ati x800 GTO than a 9800 pro? I could not afford to get a whole new PC, but if I just got the new card, would it make much difference in real terms? (but i need to buy the PSU first!)

 :rolleyes:

I'll have to research the cards, I've not seen the stats on the x800 GTO.  I'm out of time tonight, but I'll take a peek at it tomorrow (hopefully) and get back to you.

Update....

I have got a 650w powersupply. Its a sort of gold colour. I've installed it, and it seems to be running ok. It's got 3 fans built into it, so it should be cool.

My old powersupply (and this one now) was powering: the graphics card fan, 3 case fans, 4 small fans fastened to the 2 hard drives, (2 each) 2 dvd writers, one of which does dvd RAM disc, a floppy disc, and at times the digital TV on a USB port. Things that had thier own powersupply were: printer, scanner, external hard drive, and usb hub built into the monitor.

do you think thats too much for a 400w power supply? I just added to it over the last 2 years, never gave it a thought.

BTW, I didn't mean you to go to any trouble, I just wanted your best guess kind of thing on the cards. seems I get about the same frame rate weather i set UT2004 to low, normal, or high settings for textures.

It's no trouble, I don't mind looking, it was just hard to find benchmarks on the x800 GTO card.  I did finally get a chance to look around.  The x800 GTO is faster than the 9800 Pro from what I've read, however most models are PCI-Express.  The only two AGP models I saw were close to $200, and had 256 megs of RAM as opposed to the 128 meg models.  The x800 XL is faster, and about the same price, but I didn't see any AGP models.

I'd say it was possible you were overloaded if that's all you had was a 400 watt PSU, but it would depend on how many devices you were running at the same time.  I don't know what the power demand on the digital TV is but if it has no external power jack, it could be significant.  The hard drives and DVD drives together, if all were in use at the same time, especially with video card in a game setting could tax the 12 volt portion of your PSU.  If it didn't have a high enough current rating, it's possible it was overloading intermittently, resulting in an eventual failure.  I say possible because, again, I'd have to know what the current ratings were for your specific devices, including the PSU to be certain, and you'd have almost certainly experienced some crashes during gameplay, etc, well before losing the power supply.  Personally I think it's more likely it was a component defect that brought it down.

For the record, case fans typically draw only a small amount of power.  Even my mighty 92mm Tornado that can push 112 cubic feet of air a minute at full speed only pulls 12 watts of power maximum.  Most fans only draw 4 watts at most.  Video cards, hard drives, and CD/DVD drives, along with the CPU, are the usual power gluttons, but USB devices can draw a lot of energy as well when you consider there are some scanners now that can run off the USB port without any external AC power connection.  Let's go back to your 400 watt unit for a moment.  Even though the PSU says "400 watts" on the side, it's the amperage per rail that counts.  If your devices pull 20 amps on the 12 volt rail, and it can only supply 18 amps, you're overloaded even though that's only 240 watts.  The same applies if you have 25 amps available on the 5 volt rail, and you pull 30 amps, again only 150 watts, but the amperage is what matters.  There's also usually a combined wattage value for the 3.3V and 5V rails together.  On the newer PSU's, you also have split 12 volt rails quite often to distribute the power load over two rails, so you want to make sure you don't exceed either 12 volt rail's maximum current limit.  I know, it's a bit complicated, but you have to be very careful and check the spec label on the PSU to get the detailed specs.  The best way to be sure is to see how many amps each rail can handle, then check your product manuals' technical specs section for the maximum current load for the device.  Total the amps for all your items on each rail (5 volt, 12 volt, 3.3 volt), and you know for certain where you're at.  It's a bit more time consuming, but it's also more accurate.

Without doing the math, I'd say based on what you've stated spec-wise, the 650 watt unit you have now should be more than sufficient for your power demands.  The 535 watt Enermax I have is rated high enough to run video cards in SLI, so you shouldn't have any problems so long as your power company provides stable electricity.  :thumb:

Thanks for the advice. I had just added the second dvd writer 2 days before, taking out a cd writer. I had got around to getting a pioneer, as you recomended (I know it took 6 months, but my car HAD to be replaced first, then it was christmas etc.....) and took out old DVD writer, and put in the new, then moved the old to the position of the CD writer. it was a sony, and seemed to give me grief when used with nero6. errors etc.

anyway, my local supplier CCL, had the GTO card as AGP, and talked it up, as salesmen do. but I have another gig soon, so that might pay for the card, if nothing else blows up.

Last thing I blew up was a 19" monitor, playing Gen, on the euro server. 1024x768, with the refresh rate set to 100. it lasted as 70 minutes, then never worked again. 11 months old, and I got the money back! bought an iiyama.

Alright!  Our first casualty! :rockon:

Er, um, I mean "congrats on the free replacement monitor." *whistles*  ^_^

it basically meant I had gone blind in the middle of a game! I could still hear the match, and was killed pretty quickly, but stayed out of it until I swopped the monitor with my other PC.

I've noq got 85 on the one PC and 75 on the older PC as my refresh rates. (seemed to get a bit of flicker at 85, maybe due to the 50cycle mains lighting in the room. could get rid of the dimmer switch i suppose.