PSUs: how much power do you really need?
Before you run out and buy that supercharged diesel generator to power you 8800GTX SLI computer, have a look at this article by Legion Hardware where they measured what a monster system really needs. They took 4HDs 2X8800GTX, quad core CPU, 6X120mm fans- you'll never guess what they came up with: 550W!!, and it's been running fine for two months.
Are you currently thinking of building an SLI enabled Nvidia GeForce 8800 GTX gaming system with an Intel quad-core processor and a couple of hard drives in RAID? Well if you are then you need a 1000 watt power supply right? Wrong, but how can this be wrong with so many 1000 watt power supplies becoming available! In fact you donít even need an 850 or 800 watt power supply to safely operate such a system. After recently building this exact system we discovered that the maximum power demand created by this configuration was just 530 watts. Basically we built an Intel Core 2 Extreme QX6700 system with SLI enabled Nvidia GeForce 8800 GTX graphics cards using the ASUS Striker Extreme motherboard and four Seagate 320GB hard drives. Along for the ride were four 1GB DDR2 memory modules and six 120mm case fans as well as a water-cooling system. Even with all this high-end hardware installed we were only able to generate a maximum power demand of 530 watts.
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Oh well. I guess my 750W will be more than enough for 2 R600s. Thats until it die...
Cool Babrbarossa, that's good to know.
I bought a Corsair 620watt PSU for my new build and it's more than I need. But I hope that it's a PSU that will perform reliably for a long time and that's worth a little extra coin to me. I also put a UPS front end = I don't like power/PSU problems :ph34r:
The issue isn't so much that a person needs a 750W+ psu to power a mega rig. It's that they need a psu that's able to put out clean continuous power with a good 25% overhead so that they aren't running their PSU full out 24/7.
Unfortunately most sub-$120 psus cannot do that no matter what the box says they are rated at.
I have said this a few times, there is just no need for those giant power supplies except for some good ole E-Peen....
Oh man does that article give people the wrong impression.
It is basically saying: well, just because this PSU is powering my system, it is doing so without any problems. Not once I did a see a mention of ripple or voltage regulation in that whole article and those are two things that are PARAMOUNT when choosing a power supply. If there is excess ripple (considering the quality of that unit and the amount of stress being put on it I'm sure there is) that person is probably damaging their components without even knowing it.
It is articles like this that leave me stunned how some people deem themselves fit to talk about products they don't know a bloody thing about. It actually really pisses me off.
Let's take this apart.
Are you kidding me? With 90% of that power being drawn from the +12V rails, many 500W PSUs have their 12V OCP circuits set as around 18A (216W). Now, a pair of 8800GTX cards draws about 300W under load so then right away, your OCP will trip and shut down your computer. Again, how this guy is SAFELY running what he lists is beyond me...
Source: NCIX FORUMS - Looking to buy a Power Supply? Look here...
There is so much more that I can say but I think it is enough to advise you guys to take this article with a serious grain of salt.
HAHA! Awesome SKY- That's what we pay you the big buks for, heh?:biggrin:
and don't forget the demands of oc'ing.
OC'ing the cpu not only needs stable power, but depending on how much extra volts you give it and how high an fsb, you can easily double the power draw. Even tho c2d's are much better than the prescotts, but they also OC a lot better so the total power draw can be nearly as high as a prescott under 100% load.
Ditto for gpu's.
And longevity under sustained loads ... i am a folder ...every rig is oc'ed and runs 100% load 724.
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