Guys Whats your thoughts on PSU in regards to size, I'm looking for a quiet unit if not silent. Option A: Get just one big enough to do the job Option B: Get one bigger than required so as to not stress the unit. Any thoughts would be great to hear. Cheers Mark
Option B. If you stress the PSU then the fan will quick-in at full speed and make more noise. Especially that between 600W-650W-750W, heck even 850W the price doesn't vary much. And 600W is well over most people needs assuming you run 1 very high end single GPU. If you want a suggestion: - Seasonic X series (the fan only kicks in when it's under ~20% load - which means that it won't spin on idle, but will when you play games. It's also 80 Gold Plus certified) - Corsiar AX series (it's actually the Seasonic X seires, so pick the cheaper one) - Seasonic Fanless X series 560W (yes, it will handle a mid-high range GPU) - Corsair HX series. This one has a fan, but a very very quiet ones, one of the quietest.
i also would recommend b, to cover future upgrades, as in memory, gpu, hard drives, etc etc, no forgetting all them usb devices you might be adding
It completely depends the type of PSU you're buying. If you're system draws 350W full load you'd be much better off with a Corsair CX400 that a crap generic 700W PSU. The important thing is to make sure you know what your power draw is and then buy a quality PSU to match. If you can afford to go for a higher wattage then do so, as long as the quality of the PSU isn't compromised.
Probably option B and also one that has a 120mm fan. This will reduce the noise, also the case will matter if you want the pc to be quiet. Tell us more about your build so that something can be recommended.
The recommended wattage that manufacturers put on their hardware is waaaay overkill. They're playing it safe because they know people have shitty $10 power supplies that dont deliver half the wattage the sticker states.
As mentioned, using these PSU calculator you'll get extremely overkill wattage, as it follows the manufacture overkill recommendation. What powers up your computer is the amps. The more Wattage you have the more amps the PSU can deliver. Now, you have efficiency that comes to play. The more efficient a PSU is, the less heat and energy it needs to consume to deliver the needed amps. Here is an example of this, The Corsair AX 850W, as demonstrated by Hardware Secrets, has high quality components that can actually make the PSU be pushed well over 1000W. But why is it marked at 850W only? It's because at the marked 850W the PSU is 80 gold certified. If you take more than 850W, the PSU won't explode (which is always good), But also, is that the PSU is very efficient at under 850W range, going over, as mentioned in the article, degrade the efficiency very quickly. Higher components grade, can deliver more power, but when not pushed to their max (like the 10$ crappy power supply that many people love to use), you get very very very low efficiency, and even break/explode on you well before reaching the max power mentioned of the product.
i kindly disagree. energy efficiency ratings are generally the highest number a given power supply can achieve. different power supplies will behave differently, and there are efficiency charts floating around for most major power supplies....just google before you buy. heck corsair even provides us with a noise-to-power ratio chart:
Look at the the first graph carefully. It's well above 87%.. Let's say 88% for the sake of argumentation (both - it's lower point). That is freaking efficient, and it goes up to 92%. It only varies 5% between 50% load and max load. That is crazy high! Hence why it got the full 80 Plus Gold certified. Look at those cheap PSU's, they are probably at 30-50% (my guess) on efficiency at 50% load, hence why they are burning hot. The case of the AX 750 (or Seasonic X Gold series, as it's literally the same PSU), they claims: "At least 87%, 90%, 87%, efficiency at 20%, 50%, and 100% load respectively". Which is what the graph shows, and that 87% (lowest) is part of the approval of the 80 Plus Gold certification, which has been confirmed and approved (hence why they can put the 80plus certification claim). \http://www.80plus.org/. There is a new certification level put in place, 80Plus Platinum, where it must be over 90% efficient at it's lowest point, starting at 20% for PSU's. As for the noise ratio, you don't reach 750W on a computer, even if you have SLI or crossfire. And by then, your GPU fan(s) will kick in at such high speed, that it won't mater how much sound the fan does, as it's well under your GPU. Heck my GTX 260 fan is the loudest thing in my computer at any load level. If I stop the fan with my finger, you really don't hear the other fans (Noctua - low speed), and your right next to them (I have 4 fans). In fact, I purposely set a new fan scheme so that when I don't do anything the fan speed is at 30%, which is much quieter than the default 40%. Sure it take more time to cool off, and the fan speed up faster and faster compared to the normal schema, but hey it's quiet-er. Focusing on PSU noise, we can see that at 300W, I am not even sure that the fan actually spin (seeing the fan blades turn each rotation, doesn't count). That 5-10dbA is probably the electrical components that outputs such a noise.
maybe im understanding your last post wrong. i thought you were suggesting that unless you run a PSU very near its maximum rated load, you would get very poor efficiency and even damage the PSU. this is not the case. many PSU's have an efficiency curve similar to the corsair one i posted....with their efficiency being highest around 50% load. and while most PSU's have a rated minimum load, its usually in the tens of watts. as long as you have a motherboard plugged in, you arent going to undercurrent the PSU. if thats not what you meant i apologize
Ah ok! It's ok. Let me clarify. I was talking about the PSU having components that actually support the handling of way more power than mentioned, hence when you put the PSU at it's max mentioned load (let's say 750W for the 750W PSU, you get great (or at least good) efficiency). For instance, the 750W AX series, Hardware Secret was able to push the power it can deliver up to 1000W, and at that rate the PSU was holding very well, they wanted to go more, but this time, it's their own equipment that limited in reaching the max overload. Of course, at the overload area of the PSU, the PSU was reducing it's efficient really fast, create like the cheap PSU's, a lot of heat, and less and less mili-amps per wattage. I was noting the difference between a high end PSU, which yes cost more, but they use very high quality components that are durable to a point that even if you push the PSU to it's max claimed max power (ie: 750W for the AX 750), the PSU won't break on you, and it will still be very efficient (as it can go higher in reality). And let's say you go at 752 or 760W because you put an HDD. The PSU will STILL not blow up, and potentially damage your computer hardware. While a cheap-ass PSU, well already at 50% load it's struggling.
If you can afford to, I'd always recommend buying a quality PSU about twice as powerful as you need. The above graphs will demonstrate why. 1. It will always run quietly even when you're rig is stressed, and 2. It will actually be at it's most efficient when being used heavily, which as most on here play games, will be often. 3. You've got some headroom for future upgrades. A well planned PSU purchase should see you through a few builds and upgrades easily.
so basically your saying that quality PSUs are underrated, whilst el-cheapo PSUs are generally overrated. i agree with this. if you have a load requirement of 500 watts, youd be better of buying a quality 500 watt PSU over a no-name 700 watt PSU, as the quality PSU will likely hold up better and deliver higher efficiency even though its being "pushed harder". but, with the relatively small difference in price between a high quality 500-600 watt PSU and a high quality 700-800 watt PSU, id still rather err on the side of caution and get the bigger unit. just my $.02
Correct, put listen to Pokey as well. He has a very good point. Well I think 2x is really over kill, we would all be using 2000W PSU at such level in a high-end gaming or workstation rig. So no. But much higher then what you need welcome. For instance, if you have a 450-500W PSU under heavy load (meaning every single components including your USB ports and all, are stressed all together), like most of us, then go with a 750W, if you have 2 GPU's, go with a 850W. If you are on budget, 650W. Ok, but you do realize that the 700W PSU will break at 300W, as probably it was a 250-300W PSU which you will overload (without you knowing) at 450-600W. Also, even if nothing happens, and even if it covers you well. Your PSU will be as warm, if not more than your CPU under load. And your computer will sound like a plane reactor. I am telling you, and I insist a lot on this, I used to think like you, and even like "RAM is RAM, it's the same ****, same chip from the same manufacture". ALL My computers where causing me problem after problems and after problems. Things burning out, breaking, unstable, and so on. For my RAM story, my RAM ACTUALLY burned (white smoke goodness), breaking my motherboard. Lucky my motherboard was of good quality where the damages only got limited to that RAM slot. All because I decided to get Value RAM, Value Pack (double the value!). Every 2 or 3 years I had to change my computer... Well in 2005 I took a bold decision, I decided to get exclusively high end components. My computer almost cost twice as much. Guess what. It's been 5 years since, and the computer runs Windows 7 64-bit PERFECTLY smoothly (and confirmed with my new computer on my signature), I got to play the latest games, including Modern Warfar2, Street Fighter 4, Batman AA, StarCraft2, at max max max settings just fine (not as smooth as my new computer, but a bit over 30fps...). 5 Years, it passed form Windows 2000, XP, Vista 64-bit and now Win7 64-bit. It hold my programming project just fine, and the computer was ultra quiet from the first day to the last. Last?! Hell no! My father wanted a computer (he used to have a computer made of all old working computer parts of the cheap quality, which every month or so I had to change something, and now completely dies out (no more old parts to replace with), so I gave my old computer to him, and git a new one. But, if that even did not occur, I would still keep my old computer stretching possibly a 6th year or gaming, possibly will struggle at the end. But hey if we exclude gaming, the computer is like brand new. Most people don't believe me, as their computer did not last that long, even after upgrades. But it's the truth of thing. While most people was getting cheap hardware with P4 processors, I cashed out on quality components all around, and went with a 700$ processor at the time (first true dual core, 64-bit processor - from AMD, where it's mid range model was massacring the fastest P4 around). Yes my computer was 1.5k and 2k if you including all my upgrade (2x keyboard, mouse, speakers, external eSATA HDD, optical drive, etc), and 2.5k if you include the monitor which I got about 7 month ago (Dell U2410). TOTALLY WORTH EVERY PENNY. In fact, now I only go high-end. If I don't have the money, I don't buy. I just wait. I'll live with what I have.
Oh.. BTW. I just used an online wattage calculator (Antec Website), and apparently my rig should draw 708Watts at 90%. This is crap. It draws 490watts when benching.. I've measured it. They just want me to buy a bigger PSU Remember also, that mains line voltage effects power drawn. Power drawn at 220V will be different from 110volts. Power = current x voltage. Simples!
