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couple weeks ago i bought a new GTX 580 (thank you all for your recommendations).

 

after building it in and tweaking around, on one night suddenly the PSU made several bangs with smoke and sparks etc. i made couple years ago the typical rookie-mistake by buying a cheap noname 750w PSU.

this cheap PSU obviously did not have any sort of security things to prevent damage to other components. so i bought a new (and good) PSU. after this i found out that the motherboard was gone. ok. new motherboard built in. then i found out that also the memory was gone. so i got new memory sticks. after having all components again, which took several nervewrecking weeks (while waiting not knowing which other components are broken, if all data is lost etc.), i was finally able to bring my system back to life. fortunately the harddisks didn't suffer and the previous OS works as before. all well now again.

 

and the moral of it is to never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never try to save money by buying a cheap, chinese crap PSU. sooner or later you will regret it as i did.

:heat:

 

 

 

 

 

 

 

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Even buying a supposedly "name brand" PSU does not guarantee quality.

 

A couple of years ago, a friend had to replace the PSU on his desktop. He asked for recommendations, and I told him which manufacturers to look, and a few other pertinent details. Like most consumers, he memorized the list of manufacturers, but ignored the details :this:

 

He wound up purchasing a "budget" psu, from a recommended manufacturer. It went poof within six months, taking his mobo and video card with it. When I surveyed the aftermath :cool: , I noticed that he had ignored my advice (the details :grin:) regarding the number of rails, the amperage across the rails, the combined wattage, etc.

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This is another reason that I "over buy" a PSU. You can never have to much power, but you are in trouble if you never have enough.

 

The other thing that people forget, is that a PSU degrades over time, and can lose as much as 20% of it's wattage output over a couple of years (if run continusely like a lot of people do now days). As a result, if you keep your PC for a long time, you need to ensure you have enough power for all your components several years from when you first bought the PSU.

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Man, you had me worried - I had been thinking you might have emigrated to California or something like that!

Gawd, I can imagine what you must have gone through - no OFF, no Forum, no internet at all - that's tough!

 

Good to see you back, Creaghorn!

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One of the bad things about not having enough power is that you start getting random errors on you PC, not consistant but random. As a result, you start chasing ghosts all over the place unit you replace your PSU with a newer/stronger PSU and the problems all go away.

 

I know because when I added a second GPU last year, I started getting random blackouts & freezes (even though I had a two year old 1000w name brand PSU). When I replaced it with a 1350w PSU, ALL my problems went away because I had enough power for the two ATI 6970's.

Edited by Panama Red

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Welcome back, Creaghorn--fellow computer not working sufferer! I'm currently limited to posting at work, at least until my new computer parts arrive later this week.

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Not at all to hijack here - Creaghorn, welcome back and thanks for the sage advice...cheap power supplies can cause real problems.

 

That being said, however, I'm afraid I have to voice an opinion on topic: Unfortunately, power supplies are often WILDLY overrated. What I mean is there is no way the 'average' computer is going to need anywhere near 700 watts, much less 1000+. Now, before folks start screaming, let me explain a few things:

 

Power supply manufacturers (even God forbid the "name brands") learned a long time ago that even the most novice of computer users - with not a shread of electrical knowledge - figured out that more watts = more power. Laypersons interpretation? Bigger number of watts must be better. Especially if there's a brand name on the box. Well, uhhh...no, not really. Not at all, actually.

 

Everyone knows 'gaming' computers are generally fairly demanding. Adding a hefty video card or three will obviously increase what the PSU needs to provide, as will lots of RAM and overclocking...everything adds load, electrically speaking, but not many things add load like these few do, generally. Certain CPUs are fairly greedy about power, but even that's not that bad and many newer CPUs were specifically designed to do more while drawing *less* current and therefore generating less heat (watts). The core i7 2600k I have, for example, is rated at 95 watts. Some of the faster old Q-series Core2 quads were 130 watts, and that's getting on up toward the extreme. The QX9775 Extreme was a *very* rare 150 watts.

 

The graphics cards are the worst offenders, we all know that. But, as an example, the Radeon 6970's mentioned above are rated around 300 watts, and that's maximum, according to most of what I can find. I found several sources stating the TDP - thermal design power - as 250W, even less than some of the references I saw for a "max power", so I'm estimating on the (very) generous side by giving it 300 - in reality IMO, they'll never draw that in real practice,

 

But, for the sake of argument, let's say you have 2 of these 6970s, and both are drawing at worst case rates; that's 2x300...plus let's add some for a hungry CPU at 130 watts; maybe overclocked we'll say 150W. Add all that together, we've covered the worst offenders, and we're barely at 750W.

 

@ Panama Red - I don't doubt for a second your experience was exactly as you described it. What I seriously doubt is that you were getting anywhere near 1000 watts out of that power supply, because (even though you don't give specs) I'm going to hazard a (very) wild-ass guess your system would draw nowhere near 1000 watts - and certainly not 1300. I'd venture you're somewhere around 700-750W, and that's being generous and leaving some headroom. I use several wattage calculators, some even allow 'derating' for heat over time/age/caps - and I'd welcome the chance to use your actual system specs, but I tried to imagine a reasonably "typical worst'" scenario and still only got around 800-850W, using an aggressively overclocked 6-core CPU, two high-rpm SATA hard disks (like WD Velociraptors), aged caps, and two 6970 cards, etc and so on.

 

Naturally, putting in a new, high-quality (I assume) 1350W would keep those two 6970s very happy, I'm sure...but you have to agree that it doesn't mean that 1350W was ever necessary to begin with, nor does it mean that your system is actually drawing 1300W right now. It just means your old unit wasn't up to the load your system presents - a number that is, as yet, unknown. Again, I'd welcome the chance to determine, roughly, what your system draws.

 

Of course, having extra headroom doesn't hurt. But power supplies are one of the areas I see people just way over-doing, and without any real need or understanding of what the numbers mean.

 

I decided to chime in here because the original point was not to buy cheap power supplies, and I couldn't agree more - but that doesn't mean it's necessary to over-rate power supply, either. For most single-card users (even fairly high-end gaming setups), a high-quality 700-750W power supply is more than adequate, and for two cards, depending on how much other junk you have in a system, somewhere around 850-900W is a probably enough. The point the OP was making is crucial, though, and that is to get a good, high-quality power supply. A well-known brand name, by itself, unfortunately isn't enough. Some of these companies farm out production of their 'branded' power supplies to other vendors, who also make some of the cheap, no-name units.

 

Do the research, buy quality rather than quantity.

 

Just my $.02

 

Incidentally, I know I use the term 'draw' a lot when I refer to these power supplies, and it's not the most technically accurate choice of words. The proper terminology when discussing wattage is actually "dissipate". I saw "draw" because I'm generally referring to current, which is in fact 'drawn' by the load - and is the determining factor in wattage, at a given voltage. I also say draw because I believe it's what most people understand.

 

(PS. Very few PC power supplies truly have more than "rail" in them, as well. Unfortunately, the marketing types also determined that laypeople understood "more rails = better". Again. not necessarily the case.)

Edited by Tamper

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Welcome back, Creaghorn. I'm sorry to hear of your woes. Quality is definately more important than saving a few bucks when it comes to buying a power supply. Hopefully that's the last of your troubles for awhile. Good to have you back sir.

 

Hellshade

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Tamper:

I "draw' over 800 watts normally on my game PC in it's current configuration because I have an OC'ed i7 975, five HD's, two 6970's, two DVD R&W, one sound card and five fans. That is why my three year old 1000 watt PSU (which apparently degraded to below 800 watts) could not keep up the power when playing my heavily modded flight games. The PC was fine as long as I had my old 4890's video cards in it, but when I upped my video cards, it was to much for the old PSU and that is when my problems started..

 

 

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my old PSU had also 750w. usually if it's not enough it should go off instead of exploding. and even if it explodes there have to be some sort of securitystuff to prevent the current to break other parts. one bang, a little bit luck, that's it. but my PSU made about 4 bangs.

anyway. of course sonner or later every PSU breaks, even those with good names, but they shouldn't pull all other parts into the grave also...

 

 

 

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Tamper:

I "draw' over 800 watts normally on my game PC in it's current configuration because I have an OC'ed i7 975, five HD's, two 6970's, two DVD R&W, one sound card and five fans. That is why my three year old 1000 watt PSU (which apparently degraded to below 800 watts) could not keep up the power when playing my heavily modded flight games. The PC was fine as long as I had my old 4890's video cards in it, but when I upped my video cards, it was to much for the old PSU and that is when my problems started..

 

Well, see, that's sort of what I meant. The thing is, you don't "normally" draw 800 watts. Even though I had to guess, I tried to go worst case - I think I used an agressively overclocked 980X, the two 6970s you had mentioned, an add-in PCIe card (i.e. your sound card). OK, so I only used two high-RPM SATA disks, one DVD and four fans (but yes, I did allow for all that). Still, the 800W range is about MAX for this configuration, not what it runs at typically.

 

As I said above, you didn't post any system specs, but made a guess and said "I'd venture you're somewhere around 700-750W, and that's being generous and leaving some headroom". Turns out your system is fairly stout, so my first guess was a little bit short (but only a little). Not bad, considering you didn't post specs. I did say further down, that " ...for two cards, depending on how much other junk you have in a system, somewhere around 850-900W is probably enough". Turns out, you system isn't that far from what I guessed, even with all the heavy hardware.

 

Here's some things that matter:

 

- The hard disks are not always spinning, and they draw much (much) less when they aren't. If they are spinning more than about 10% of the time *total*, something else is wrong.

 

- The DVDs, unless you're burning a disk, are not firing thier lasers; unless the platters are actively spinning, they are using almost no power. I can't speak for everyone, but I *hate* listening to a drive whine over a disk I'm not even using - I take them out.

 

- Your CPU, even heavily overclocked, does not run max at 100% all the time - not even close. Unless you run Prime95 or some other benchmarking/stress testing utility for your games, it's not drawing 100% of the max, all the time. Also, I've owned two i7's, one 1366 and one 1155, and on the machines I've overclocked of this class, you can turn off EIST all you want but they *still* throttle back almost immediately as the load on them varies.

 

- The graphics cards - even though I'm sure they are very nice - are also not operating at 100% of max, all the time.

 

Have you actually measured the 'draw' of your PSU? I'd bet money that, even though it will peak and fall, you're probably running well below 800W, typically. You might be closer when you're actually gaming, but even then it won't be full load all the time. Prime95 loads my CPU 100% across 8 workers...but even Rise of Flight does well to average 60% across all 4 cores, and it's fairly CPU greedy. 60% of the load = 60% of the watts. Most PCs are almost *never* loaded 100%, and even *if* they are, they're not that way for long (unless you're intentionally stressing it for testing, are asking far too much, or are just plain crazy and want to see something burn up).

 

My point is that people confuse what they need MAX with what they use on average. It means you needed a PSU that was MAX about 850-900W - that's around 66% of a 1350W unit. Your old one probably failed due to age, and being a name brand didn't help it (sometimes it can, but still just postponing it).

 

Yes, you need some head room. But it's just plain not necessary to "oversize" a PSU by 50%. Get something to handle your max, maybe allow 10-20% for durability and overhead; this would've put you around 900W. You can always spend more, of course, just not really necessary and won't guarantee no failures, even if you spend millions. (Like that song Dust in the Wind, "All your money won't another minute buy")

 

One thing that will definitely affect the life of a PSU is heat. As I mentioned, watts is actually a measurement of power, dissipated in the form of heat. It really doesn't matter how big a PSU you get, if you obstruct airflow or don't keep it clean, it cannot dissipate heat and wil fail. And, sorry, blowing it out with canned air doesn't count (although it is a good way to ruin the fans you do have).

 

Buy a quality unit, keep it cool and clean, make sure all the connectors are kept tight and secure, and do not use splitters or other adapters unless there's no other choice (even then, consider getting someone who knows how to solder to help). No need to over-rate a PSU.

 

@ Creaghorn - yes, it's really regretful. Depending on the company/engineers, they really do provide a lot of 'safety' against things like that happening; but there are always exceptions. It is just not possible to foresee/prevent every possible failure and all the possible consequences. I've seen (and done) some very ugly things to PSUs, both intentionally and accidentally, and for the most part they are very forgiving. For example, as a test, we took a switch-mode PC power supply from the equipment I work with, and put an almost direct short, immediately across the outputs (0.2 ohms, as I recall). The power supply, being switched-mode with 'crowbar' over-current protection, dutifully shut itself down, and attempted to restart (to shut down again), for the entire two hours we ran it like that. The output voltage on the 12V line never got above 0.3v before the OCP kicked in. And after the test, the unit worked just fine. So there is some protection, and it does work (if in a "good" design).

 

But, unfortunately, not always :(

Edited by Tamper

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Following the post above, and my comments concerning keeping your PC clean:

 

I was just over on another site reading a thread where a few of the folks there were showing off their triple-monitor setups; some nice pics posted and all that. Then I noticed that, for all three guys, the pictures *appear* to show their PC cases sitting down in the floor.

 

My response: :yikes:

 

I mean, here are three different guys, obviously far enough into flight sims to have triple-monitor steups; apparently well-enough off to be able to have them. And I'd bet that each of these fine gentlemen would tell us they know a thing or two about PCs and power supplies. But it looks as if they all put their machines in the floor. I get that it probably seems the most obvious place, really, I do. And it's definitely out of the way, so you can place all your controls up on the desktop, within arm's reach (who needs to reach the chassis all that often, right?).

 

But the floor?

 

Let me tell you why this shocks me...it's almost as if these folks, who would seem otherwise computer savvy, have never cleaned one out before...or, if they have, they've never quite done the math that even in the cleanest of homes, there's a ton of dust. Gravity being what it is, the dust is always falling to the floor, where your sporty, multi-gajillion-dollar flight sim is now doubling as a Hoover vacuum. All those fans, sucking up all that dust, and feeding it where? That's right, straight into your humongous PSU - where the fan most likely pulls harder, the hotter it gets.

 

IOW, more dust, please - with a side of dust.

Don't get me wrong, I appreciate the value in re-purposing equipment. God knows, the economy being what it is and all that, we can all afford to get more from our computing budget. I'm just not sure it's a great idea to use your computer as a vaccuum cleaner.

 

And, to bring the point back to the power supply topic: This is something I was referring to before, concerning heat and keeping a PC clean. Never (ever) run a computer in the floor (well, OK, for more than a temporary bit, and only then if you must). Most people do not clean computers as often as they should; the power supply itself is enclosed and traps more dust, but is almost never removed and taken apart during cleaning; and many cases do not use intake air filters. Often the only thing done to 'clean' the PC is blowing canned air (*uggh*) through the inside, and putting a PC in the floor worsens the problem substantially.

 

And then folks wonder why what should be an adequate PSU has problems or won't work reliably. Even some of the more knowledgeable and experienced people, who have the wherewithal to acquire these magnificent rigs, do this. So, a few questions:

 

- Is your PC in the floor (or within a foot?)

- Do you clean the PC at least once every couple months?

- Do you have filters on the fan intake holes?

- Does your cleaning involve using canned air? (And generally nothing else?)

- Do you ever remove the PSU, take it's cover off and clean it out?

 

No answers required, just food for thought.

Edited by Tamper

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Tamper, all the PCs of all people I know - mine included - are high tower cases, standing on the floor under the workdesk.

Why should I have that gigantic monster on the table?

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Well, you're kind of making my point, Herr Mahlo :) It's a very common mistake, IMHO. And that opinion is based on decades of cleaning very nasty computers - some to the point that fan(s) had stopped entirely due to dust, followed by other hardware failures, caused by heat. I've also repaired plenty of machines where the clear culprit was heat, brought on by excessive dust and improper/inadequate cleaning.

 

There is no law saying you cannot keep a PC in the floor. I'm just offering some free, well-thought-out advice, and actually explaining the reasons for the advice. If you don't mind a (much) more aggressive maintenance schedule, you can certainly keep one in the floor - but (if we're being honest), who is going to take a PC apart once a month and clean it?

 

They just don't do it. Yet, it's no different than your automobile: Operate it in more demanding conditions, and the scheduled maintenance requirements are increased.

 

Also, as a note: It's not one-or-the-other; desktop-or-floor. There are many alternatives to the desktop itself, and in my experience, even a foot off the floor makes a big difference. Inexpensive 'side tables' are an option, even *very* economical plastic "milk crates' or other boxes. One of my sons had at one point a small PC desk that had no room for the PC itself, so I used a piece of inexpensive MDF ('particle board') and fabricated a shelf on the side.

 

Let me put it this way: Some of us spend an awful lot of money (and time) on our computers. Obviously, no one likes when they fail, nor does anyone have any "extra" money to blow on unecessarily buying over-powered equipment (at least I dont').

 

Is it not worth it to spend a little on taking care of these things that represent such a large part of our recreational lives? Denying the need for preventive measures - to include cleaning *and* proper design/implementation, as well as identifying ponts of failure - is a sure path to frustration and extra cost.

 

I hope this makes sense; cheers to you, sir.

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I didn't mean to get cheeky, Tamper, and yes, I see what you mean; and of course one should open

the side panel every now and then, and clear all parts from any dust.

But my flat is not that dusty, that I find much dust, when I open the PC once every 2 months or so.

See, my computer casing is 50 x 50 x 20 cm in size - I wouldn't want to have that on my desk.

What I can really recommend is a water pump cooling system for the CPU - works great; no high

temps anymore.

Edited by Olham

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Hi Olham, I sincerely took no offense to your questions/comments - in fact, I welcome the questions. In my mind, good technical advice always withstands scrutinty, so I would absolutely encourage any questions at all.

 

Based solely on what I've seen of you here, I'd guess you are certainly among those who would be diligent in upkeep - the highest order of compliment I could pay you :drinks: I'd also venture that many are *not* so diligent, if the truth were to be known.

 

However, as we all know, not everyone is the same, nor is every situation. There are different climates - this time of year in the southeastern US we have terrible pollen problems - visible pollen, like huge dust clouds sometimes. This year has broken all records by some 15-20 *times* as much. Some folks have pets, which can add both dander and fur to the air.

 

How many people live in a place factors in (movement disturbs lying dust), as will actually cleaning your place (which stirs up a *lot* of dust, and depending on how good your vaccuum machine is, it may or may not take all out of the air...some actually release dust *back into* the air). Whether/how often you keep your AC filters changed (as well as what type filters you use).

 

Another factor that matters is the number of fans in a case, along with their size and placement. I have seen surprisingly few cases actually feature intake filters (I modified my chassis to accept 2x120mm intake fans with filters). Also, the type of power supply you have matters; some have fans that run all the time, some are thermostatically controller. Some are 'top-mounted' in the chassis, some are 'bottom mounted'.

 

There are obviously many factors. All that being said, though, irrespective of the contributing factors, what I see is a lot of dirty computers :) And, as it relates to this thread - the discussion of power supplies - I also routinely see a lot of misunderstandings about heat, dirt, power, watts, and PC maintenance. Like I said earlier, I spoke up here because it's very common to 'over-size' a power supply..but (in my own opinion) not really needed.

 

On an individual note, I do have to admit a 'pet peeve' of mine is the trend toward bigger and bigger power supplies, where the electrical facts just doesn't support it. What *does* support the 'bigger and bigger" trend, though, is power supplies that are cheaper and poorer, and therefore folks think you need to overrate a PSU to make things work well.

 

As to the size of the chassis, 50x50 cm - while it is not "small" - is probably typical among gamers' PCs - you almost must have a chassis that size to accomodate graphics cards that sometimes exceed 25.5cm. You are correct, few people want (or have room for) something that large on the desktop. Mine is that size, and I have a small 2-drawer side table I keep it on; just next to my desktop; about 24" tall, which puts the DVD drive right about shoulder high. As I said above, there are numerous inexpensive options.

 

Finally, concerning the liquid cooling, it is a great idea for cooler CPUs. Unfortunately, these days the case has quite a few fans of its own, as well as the video cards and power supplies. A good part of the "work" that electronics do is actually dissipated as heat, and something has to be there to move the heat away from many components beyond just the CPU.

 

As always, nice talking to you :)

Edited by Tamper

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So I got home this evening, and given that I mentioned 'electrical facts' above, I thought I'd do some "real world" demonstration. I measured the voltage and current at my PSU, at idle and through several games that are all fairly demanding for both CPU and graphics, including Rise of Flight and Age of Empires 3 (still, perhaps surprisingly, one of the most demanding games I know of after all this time). While I readily admit this was a 'short' test, I certainly tried to not take any short cuts, making several measurements while playing at various levels, with more and less objects/units, while loading, sitting idle at menus, etc. I let the ammeter 'hold' at the max reading for each of these conditions; I then took the voltage readings I had gotten prior (on the cord coming from my UPS), and literally 'did the math'.

 

Result? The MAX my PC drew was 404 watts (and less than 350W for RoF, which is fairly demanding in the graphics department). If you use one of the respectable online calculators, you'll come up at a recommended max PSU for my machine of about 700W (mine's got some miles on it. I originally bought it to do SLI with 2 older cards, and it did just fine there, too). That's because most of them - at least the ones I've ever used - already tend toward substantially over-calculating max. Think about it, otherwise they'd be opening themselves up for a lot of trouble with these 'calculators'.

 

404 watts. And while my machine isn't the biggest monster by a long shot, I guarantee you that most people, if asked, would never believe it uses about 400W max. They'd say you were crazy to try and use a 450W PSU...but, if it were a good supply, actually capable of delivering 450 continuous watts, it would have no problem.

 

PC's just don't draw what a lot of people have been lead to believe. Marketing misleads people into believing more watts is automatically better (same goes for more rails), when it just isn't really true, and it just isn't usually neccessary. I would put a computer like Panama Red's probably only measuring in the 700W range (max - with those two powerful video cards, 5 hard disks, etc.), so it's difficult to imagine a machine that would actually draw 1000W (although people do sometimes put 3-4 video cards in them, these days...I bet it's really rare, even around here).

 

Creaghorn started the thread to say don't buy cheap power supplies; he's absolutely right. Buy quality, not bigger/more watts. Use a good PSU calculator. Add a little for overhead, aging and (optionally) expansion. Keep it cool and clean; put some thought into where you place the machine. You probably won't require a huge power supply (or the huge cost that usually goes with). Needlessly over-rating a power supply can wind up costing you serious money; $100-150+ beyond what you really need to spend. Put that extra $ toward a better CPU or video card :ok:

 

Just my opinion folks, and my advice - as always, take it or leave it as you will.

 

Best regards.

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