Do I need a new PSU?

Ever since I upgraded to a nVidia 7800GS and 2GB DDR400 RAM, my computer just randomly shuts off (at least once a day if I have it on the whole day). I can still hear the fans going (on the processor and video card), but the computer has shut down and I need to switch it off and wait a few minutes, then start it up again.

I was talking to a friend, and he said that perhaps my PSU is not powerful enough (I have not checked how many watts it has), and that I should go and buy a 450watt PSU as that's what is recommended for the video card.

Do I need a new PSU? Will any fit into my computer? Are they easy to install?

The PSU is the big metal box with all the power cables in that sits at the top back of most computers. It's usually pretty easy to remove and replace, just remember to plug everything back when you get the new supply.

The only other thing I'd recommend checking first is whether it's because it's over heating.

How would I know if it's overheating, or just not giving enough power?

I would buy a new power supply unit and find a way to check if the system is overheating.

This can be a very debilitating problem and can lead the ruination of the entire processor, graphics card, and power supply unit.

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Originally Posted by Omecle

How would I know if it's overheating, or just not giving enough power?

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Check that your fans aren't too dusty. This happens quite a bit especially with laptops.

As for the test, do an experiment. Run a high-end 3rd game at full quality and see when it turns off. Then restart the PC and leave the empty desktop open for a bit. If it goes off on the first but not the later, it's the overheat.

Oh okay, well when I am running WoW for awhile (even when AFK most of the day) and do other things like some audio stuff with the keyboard, it shuts off and then when I turn it back on (pretty much straight away) it runs fine for the rest of the day.

This has been happening at least once a day. So I don't think it'd be overheating, otherwise it'd want to shut it off all the time.

I don't know. Sometimes, problems like overheating don't always have a logical pattern.

The random power resets are occuring far too often. I would definitely get the new power supply unit; if the problem persists, I would look into a cooling system.

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Originally Posted by Grinenshire

Check that your fans aren't too dusty. This happens quite a bit especially with laptops.

As for the test, do an experiment. Run a high-end 3rd game at full quality and see when it turns off. Then restart the PC and leave the empty desktop open for a bit. If it goes off on the first but not the later, it's the overheat.

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The more demanding the task, the more power your components will draw from the PSU, so this test won't work. :p

It's probably quite likely it's overheating. Try this piece of software that will give you information about stuff on your motherboard, like temperature and voltage sensors. Run it immediately after a crash and let us know what it says.

When I install that software, I select the motherboard type IBM and it says none of the models are supported. I'm not even sure what model it is.

Straight after a reset, when booting up keep tapping the del key until the bios screen loads. From here go to it's hardware monitoring feature and note down the details and post them here?

I would also say this sounds more like an overheating issue. The fact that you need to wait a bit before you turn it back on is evidence for that. I don't see a reason why an overloaded PSU would work better after a few minutes of cooling down.

Most new computers are set to cut the power before the temperature gets high enough to damage it, but I'm not sure if that applies to the graphics card temperature.

How many extra devices do you have? If you only have an extra hard disk and this new graphics card, then I would say it's very unlikely for it to be a too weak PSU. My PSU is 315 watts, and I've got four hard drives and two DVD drives, still no problems at all. IIRC, most PSUs are about 200-250 watts.

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Originally Posted by o_O

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Originally Posted by Grinenshire

Check that your fans aren't too dusty. This happens quite a bit especially with laptops.

As for the test, do an experiment. Run a high-end 3rd game at full quality and see when it turns off. Then restart the PC and leave the empty desktop open for a bit. If it goes off on the first but not the later, it's the overheat.

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The more demanding the task, the more power your components will draw from the PSU, so this test won't work. :p

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I think it would actually. The difference between the power demand and the overheat is quite simple really. Time. Once you start a high-end application, the power will be immediately needed in all of the components, save the cooling system, and thus you'll see the effect right away. If it is the overheating, you'd still have to wait for a couple of minutes for the hardware to heat up to the level where it starts overheating. Either way, you should see that it's not the PSU once all the fans are working on full power and the PC is still on.

Apart from that, what Mirage said about the boot-up lag.

I only have one HDD, two optical drives and the graphics card. Oh and a fair amount of USB devices if that counts for anything, though they don't take up much power at all (most have to be plugged into the wall anyways).

My friend also has a nVidia 7800GS, and he said that they require a 450watt PSU. I will read the manual again once I find it though, but yeah, 250watt sounds kind of low.

And I only have to wait at most, 2 minutes before rebooting it.

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Originally Posted by Grinenshire

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Originally Posted by o_O

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Originally Posted by Grinenshire

Check that your fans aren't too dusty. This happens quite a bit especially with laptops.

As for the test, do an experiment. Run a high-end 3rd game at full quality and see when it turns off. Then restart the PC and leave the empty desktop open for a bit. If it goes off on the first but not the later, it's the overheat.

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The more demanding the task, the more power your components will draw from the PSU, so this test won't work. :p

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I think it would actually. The difference between the power demand and the overheat is quite simple really. Time. Once you start a high-end application, the power will be immediately needed in all of the components, save the cooling system, and thus you'll see the effect right away. If it is the overheating, you'd still have to wait for a couple of minutes for the hardware to heat up to the level where it starts overheating. Either way, you should see that it's not the PSU once all the fans are working on full power and the PC is still on.

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The reason I said it wouldn't work is because spontaneous shutdowns aren't a usual symptom of a faulty PSU. You're much more likely to see lockups and hear funny noises from the optical and hard drives. That's because the highest-drain devices on a PSU are the ones which require power for kinetic motion.

If it's overheating, unless you have an old CPU, you're going to see random shutdowns because pretty much every PSU since 2001 has had automatic shutdown capabilities beyond a certain temperature, to save it burning out.

Given the number of devices on Omecle's PSU, only a faulty one would be weak enough to not be able to power them.

So, I should get a new cooling system? How much do those things go for. o.o;;

So even though his graphics card says it needs a 450w psu, you guys don't think it's that? I'm asking because I'm about to get in the same boat as him, all the graphics cards I've been looking at ati 1600, geforce 7600, require a 350w psu and my computer only has a 300w. :O

I would not completely rule out the PSU being too weak. However, I would first see if cooling the system down would help(generally I don't see random shutdowns from a weak PSU). I do this at home by pulling the computer out into an open area(that is safe for it to run in) and then opening the case up and have a couple fans blowing cool air past it(note: not into it, you just want to keep as much 'warm' away from the normal fans as possible).

If it still shuts down randomly than you may conclude that the PSU might be too weak(it may be uncommon but I have seen a weak PSU cause random shutdowns once in my life).

As for keeping it cooler. Keep these in mind:

-You want easy airflow around the case.
-Don't put it towards one of your furnace registers(hot air being spat out right beside the computer = bad).
-Make sure to keep the insides and fans clean of dust. You would be surpised how much dust can increase a computer's temperature.
-Make sure you have air circulation in the room it is in(dead air doesn't really help it, though it doesn't exactly hurt it either if the air is cool).

As for the stated watts required for hardware... I tend to observe that you don't always need the 'recommended' watts to actually use the card reliably. I hear that can be awfully hard on your PSU though.

I seriously doubt a graphics card can *require* a 450W PSU. How would the manufacturer be able to tell how many other devices are present in the computer?

As for your USB devices, I think one USB port can only supply a maximum of 0.5 amperes. At 12 volts, that means 6 watts.

Cooling systems can vary in price. It is a common purchase for computer enthusiasts, so I'm sure that you'll find something you like after browsing the appropriate places.

Are you going to make an online purchase?

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Originally Posted by Roogle

Cooling systems can vary in price. It is a common purchase for computer enthusiasts, so I'm sure that you'll find something you like after browsing the appropriate places.

Are you going to make an online purchase?

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Yeah I was thinking of buying from here, but I don't know anything at all about cooling systems. And I really don't want to spend that much to be honest. Would it be worth getting water cooling or just putting another fan in?

I have my computer in a place where air can flow through the vents on the casing quite easily. So I'm not sure if it's that. I'd say the graphics card really generates heaps of heat, but it has it's own fan and ventilation so I'm really not sure.

It's absurd for a single GPU to require a 450W PSU. The only reason they'd say that is to protect themselves from lawsuits from people running 5 HDDs, 2 optical drives and and array of assorted PCI devices and don't realise that PSU power is distributed.

You could quite easily run that GPU on a 300W PSU. Probably lower, but to be on the safe side I wouldn't. :p

As ShunNakamura said, you'll want to improve airflow around the case. My PC has two intake fans and a large extractor fan directly above the CPU, as well as a fan attached to the heatsink of the CPU. It's important you cool down the CPU, since that is what overheats. You could also replace the heatsink on the CPU, since old thermal paste on a CPU becomes more insulating and less conductive. That's not too difficult a task, but you do need to be very careful so as not to damage the processor.

If you wanted to go one up, you could go for water cooling; there are a few fairly cheap kits around and they've gotten pretty quiet too.
Then there's vapour chill, if you want your computer to be a fridge. And if you have money to burn. :p

EDIT: While I'm on the subject, I think adding a fan should be sufficient, unless you don't have a fan on your heatsink. You might be able to find a fan to fit on your current one, but odds are you'd have to find a fan/heatsink combo. From that link you posted, I recommend something like this for a heatsink. The reason for that is that the greater the surface area of the heatsink, the more heat it will radiate and faster. Remember that radiating heat back into the case is nigh on useless, so you need to have a fan to extract the hot air from the CPU.

Well I was guessing I'd only need to spend $50AUD or so on a new fan rather than $200+ on a whole cooling system. I just want to know if they are easy to install and that it is the reason it keeps shutting down. I have cleaned out all the dust inside and on the ventilation holes, and it's got a lot of open space around it.

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Originally Posted by Omecle

Well I was guessing I'd only need to spend $50AUD or so on a new fan rather than $200+ on a whole cooling system. I just want to know if they are easy to install and that it is the reason it keeps shutting down. I have cleaned out all the dust inside and on the ventilation holes, and it's got a lot of open space around it.

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Umm.. you could do a n00b check. Open the case and point a normal household fan at the PC. Then see if it goes off.:D

(not recommended)

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Originally Posted by Omecle

Well I was guessing I'd only need to spend $50AUD or so on a new fan rather than $200+ on a whole cooling system. I just want to know if they are easy to install and that it is the reason it keeps shutting down. I have cleaned out all the dust inside and on the ventilation holes, and it's got a lot of open space around it.

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You'll easily get a case fan for $AU15. Generally, you pay for silence. The more it costs, the quieter the fan. They are very easy to install if you already have a hole for one there. If you want to place it strategically over the CPU but don't have a hole there, it's a little more complicated to case-mod your box. Personally, I wouldn't do it unless the case has a removable side panel.

You'll pay a little more for a heatsink/fan combo, but this has the advantage of removing heat directly from the processor. The hardest part is removing the old heatsink.

One more thing you should check is whether or not each fan in your case is working adequately. If you're getting funny noises from your fans, the bearings have probably gone and need replacing. Hold your hand beside it to feel the air. If it doesn't cool your hand, you might want to get a more powerful fan.

The mere fact that you mentioned you should UPGRADE to a 450 W PSU tells me you should at least do that.

Unless you have a 400 W PSU. I'm thinking you have a 350W and nobody should use something that weak :)

Why? My 340W PSU doesn't have any problems powering 4 hard drives, and it can probably power one or two more.

There's no need for an overdimensioned PSU in a regular desktop PC, so unless you're using your PSU to power your monitor (and who does that nowadays?) 350 watts should be enough for Omecle.

Though, I think I might want an additional, or a stronger PSU if i were to connect both another hard drive and a graphics card that require more power than it can draw from the AGP/PCI-E port.

Ah I see, well it didn't happen today. Tomorrow I will give the whole computer a good inside cleaning and see if that improves it at all.

Hopefully I won't have to buy anything for it.

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Originally Posted by o_O

You'll easily get a case fan for $AU15. Generally, you pay for silence. The more it costs, the quieter the fan. They are very easy to install if you already have a hole for one there.

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Go with ball-bearing fans and stay way from the plain blade fans. Those are cheap and will not last you very long.

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The hardest part is removing the old heatsink.

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I'd argue installing the new hsf is a more difficult task, of course depending on the design of the hsf and cpu. Removing my old hsf was just a matter of getting a flathead and popping the brackets up, but installing the new one required a little bit of modding to the bracket design by bending the clips. I fear the day when I have to reapply the thermal paste and have to deal with that again. :p

a 700w power supply is not a 700 what power supply. Go for a proven brand, and make damn sure its got good ampage. The power supply is the most important unit hands down. A bad PSU can destroy your comptuer in seconds. "Thermaltake" and "PC Power & Cooling" are two general companies that I can recommend from personal use. Don't ever underspend on the PSU - it is way too important.

I lost a machine to a 100 dollar power supply. Mobo, cpu, and gpu all fried. :( Thank god for newegg's policies on bunk parts. I got a replacement for all and went with a Thermaltake equivilent. runs like pie.

Strange, I don't think mine cost much more than that, seeing as my case was already fitted with a PSU, and the case probably wasn't a lot more than $150.

$100 is more than enough for a desktop PSU. Must have been a lemon.

So it is really important to have a psu that measures up to what the card says it needs? Or would a bad psu be a bad psu and smurf up whether or not it's trying to power too much? @_@

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Originally Posted by Yamaneko

$100 is more than enough for a desktop PSU. Must have been a lemon.

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not sure, I have heard otherwise at least when purchasing higher end PSU's from multiple people and coupled with personal experience. Plus the fact that to get a 700w ranking, that just has to be met in intervals of peak power, not constant ampage, which means that you can get a high variance in your psu output, which is never good for a computer to have.

Might I add, that if your case supports multiple PSUs, do it! Put your drive string on one of its own.

I do agree that a hundo is fine to spend, a good ball park range, but look at the stats on the psu, and make sure the company has a good reputable name. I gave you two that I have loved. I personally end up spending between 150 and 230 (us dollars) on my PSUs.

Meca, from the evidence that I have observed and been told time and time again, the rating on a PSU is nothing to simply go by. I believe the rest of your answer lies above. In short, you want to be able to power your video card to its threshold, but you want to make sure that the power isn't just peaking at the card threshold. You want the power needs of the card to be met through and through.

Maybe if you're going to power a workstation with a bunch of HDDs and optical drives. Two PSUs is overkill and a waste of power. Omecle just wants to game so a decent wattage with good amperage on the 12V rail (24A or more) will be fine. Just use the filters on newegg and read the reviews for different brands.

You'll hate me for this, but .... it depends.

What you have to do is look up the actually usage(not the requirements, the usage) of what equipment you have in your PC, then you add it up. If it is less than what your power supply gives out you are good. If it is more, you need a bigger PSU.

Anyways I haven't had any luck finding the exact what usage of this nVidia 7800GS card. But I have seen a benchmark test shows it to use less than 300 watts[though higher than 250] even in system with some decent equipment. However, the system was not decked out with hard-drives, optical drives, etc...

It really depends on all that you have in the system. The manufactures post those large requirements(recommendations) to protect themselves. This is because not all PSU's work the same(even if at the same watts). And this can cause all sorts of weird things concerning the card. The recommendation is basically, "Yeah with this much 'power' it is unlikely that anything bad could happen even if the power supply isn't very high quality and has lower output than what the watts would suggest."

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Originally Posted by Yamaneko

Maybe if you're going to power a workstation with a bunch of HDDs and optical drives. Two PSUs is overkill and a waste of power. Omecle just wants to game so a decent wattage with good amperage on the 12V rail (24A or more) will be fine. Just use the filters on newegg and read the reviews for different brands.

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yeah, I was mainly, saying instead of throwing out his other psu, throw the drives on it. Puts a bit of an ease on the other. Less jolting on the demand of the PSU just getting the HDDs off it. And yes, your summed sentance basically agrees with what I was saying.

No consumer card out now uses that much wattage. The box and manual quote refers to all combined components, so a 250 or 300 watt power supply is the bare minimum to power your entire machine including the 7800GS. This of course doesn't take into consideration more than one HDD and more than one optical drive. Processor consumption is also averaged by the GPU manufacturer by speculating what kind of processor people in their GPU's range will probably have.

This will give a good comparison of actual power consumption for the 7900GS and it's respective competitors.

EDIT: In response to ShunNakamura.

Very true Yams. I must also clarify, that I am generally buy enough power to run SLI, regaurdless of whether the computer has it set up now, or will in the future. For a single card system, I tend to go 500w to be safe. So yeah, a hundred bucks (and I just queried new egg) will serve you quite well.

My PSU.

Powers my nForce2 board, two Seagate drives, two optical drives and my 6600GT, a GPU notorious for its ridiculous power consumption. The 7 series remedied a lot of the power problems with the 6 series.

I've had no crashes or lock ups and speedfan doesn't report any dramatic power surges on any of the rails. It's been good.

I'd also look at getting a dual rail PSU as each rail has it's own amperage and can be dedicated to certain components inside you machine. My GPU has a dedicated 12V rail with 18amps.

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Originally Posted by Yamaneko

My PSU..

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It is getting a lot of short life expectancy reviews :mog:

Haha, yeah I noticed, but I've had mine for more than two years, so I'm going with what I got. :p

@Yams
heh, sorry, when I said
"But I have seen a benchmark test shows it to use less than 300 watts[though higher than 250] even in system with some decent equipment."

I was talking about combined total watt usage for the whole system(if that wasn't clear).

Though I am glad to see a site that has thier actually watt usage. I always have issues finding individual components power usages.

Hmmm. Thanks for the information. Somehow I don't think I need a 500w PSU, especially since all I am running is 2.8GHZ, 7800GS, 2GB RAM, 2 optical drives, 1 hard drive, and that's pretty much it.

I am still unclear as to whether it's about the PSU or the cooling. So far it hasn't happened in the last two days (the shutting off randomly), so if I can avoid buying anything at all that would be ideal.

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Originally Posted by Omecle

Hmmm. Thanks for the information. Somehow I don't think I need a 500w PSU, especially since all I am running is 2.8GHZ, 7800GS, 2GB RAM, 2 optical drives, 1 hard drive, and that's pretty much it.

I am still unclear as to whether it's about the PSU or the cooling. So far it hasn't happened in the last two days (the shutting off randomly), so if I can avoid buying anything at all that would be ideal.

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Would be cool if it'd just stop now.=]

since the problem only started after adding the graphics card and the memory it tends to point to the psu been to weak.

how many amps are on the 12volt rail? if its under 20 id definatly replace it especially if its a generic brand psu they can take out components when under strain just ask any one with a q-tec or a hiper psu :P

try putting one of these FSP psu's in your system very reliable and shouldnt take out any components if it goes bad as theres plenty of failsafes and its a good quality psu plus the 2 12 volt rails will give plenty power about 28 amps i think not looked at the sticker on mine for a while :)

FSP Sparkle Blue Storm 2 500W ATX2.0 PSU

btw one week before i rebuilt my system i put in my x800gto and my cpu points on my old sempron halved on 3dmark tests plus some stability problems = my old mercury "generic 400watt psu was struggling to hell oh it only had 17 amps on its only 12 volt rail and would of blown up big time if i kept it and i was getting similar symptoms to you"

even cpuz agreed the voltage was fluctuating a lot and that was a sempron 2800 socket A.

the fsp one is happily powering a 3700 a64 1 gig ddr400 a x800 etc plus 3 harddrives and 2 dvd drives and it will allow me to whack in a 8800gtx "possibly sli" on top of that when i get money and if i want one plus that psu is silent and wieghs about 10 times the weight of my old generic one :)

moral of the magical story is you get what you pay for and a decent brand psu will last for ages and not take out components when it blows and will last for at least one mainboard upgrade before struggling so kind of a future investment which results in a more stable pc and stable overclocking :)

on the old psu and my old graphics card there was a point i overclocked it to and my 3d marks started to drop.... same happened on cpu overclocks psu was to blame :)