PSU Calculator

I have used a couple of time. Seems quite accurate. The site calculator i mean, not the actual unit you plug into the wall socket.
 
It is fairly accurate, but I would really recommend that you keep the TDP & System Load values at 90% and select 15% capacitor aging if you intend on keeping your PSU at least 3 years.

With those settings, it showed:
System Type: 1 physical CPU
Motherboard: Regular - Desktop
CPU: Intel Core i7-940 2933 MHz Bloomfield
Overclocked: 3900 MHz, 1.45 V
CPU Utilization (TDP): 90% TDP
RAM: 3 Sticks DDR3 SDRAM
Video Card: NVIDIA GeForce GTX 460 1GB
Video Type: SLI
IDE HDD 7200 rpm: 1 HDD
Flash SSD: 1 Drive
DVD-RW/DVD+RW Drive: 1 Drive
PCI-e x1 Card: 1 Card

Regular Fans: 1 Fan 120mm;
LED Fans: 3 Fans 120mm; 1 Fan 140mm;

Keyboard and mouse: Yes
System Load: 90 %
Capacitor Aging (+ W %): 15 %

Minimum PSU Wattage: 602 Watts
Recommended Wattage: 652 Watts
Click to expand...
... and I know that my system has never drawn more than 480W (540VA from the AC Input - 90% eff PSU).

Now it is VERY important that you get a power supply that isn't max rated according to that Recommended Wattage! An example of the max rated power supplies are the Gigabyte Odin series.

I haven't used the PSU calculator in a while now, because I usually just use the TDP values of the main components, which are in my case:
CPU = 135W, but with overclocking to 3.9GHz this would be in the region of 190W
GFX = 160W x2
Total: 455W (stock) / 510W (OC'd CPU)

And as you'll see that is very close to what I've measured (510W vs 480W).
So I usually recommend PSU's based on the TDP values alone, but I always make sure that the +12V rails can supply sufficient current to the graphics cards AND I add a reasonable safety margin of like 20-40% depending on whether the user would like to OC or go for a cheapish PSU.

Currently I would recommend the following series power supplies for entry level/mid-range gaming PC's:
Corsair CX / CoolerMaster GX

Edit:
I also forgot to mention that you have to always look out for PSU's with multiple +12V rails! The dual +12V rail power supplies usually use the 1st +12V rail for the CPU, and the 2nd +12V rail for the graphics card and all the other components.
For this reason, I rather recommend the Corsair CX / CoolerMaster GX series power supplies, which both use single +12V rail designs AND they are rated 80% efficient as well. Single +12V rail design power supplies makes the calculations/estimations just so much easier.
 
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Thanks! See my response to the individual links in dark red.
Nicko said:
There actually tons of these sort of things.

http://extreme.outervision.com/psucalculatorlite.jsp
http://www.thermaltake.outervision.com/ < Same as above, but actually a tiny bit more restricted.
http://educations.newegg.com/tool/psucalc/index.html < Pretty useless, unless you only want to get a very quick estimation!
http://www.raptoxx.com/calculator.php (This one I think is probably the best) < Yup, this one is certainly the best, but in my case their calculation was off by at least 100W (it said my PC will draw up to 580W, where in reality it drew only 480W). So they recommended an 850W PSU, where a decent 650W PSU would suffice.
Click to expand...

---

Nokkie said:
more than 800watt for me, without over clocking.
Click to expand...
What is your system specs then? i7 980X with 2x GTX580?
Also, that 800W, is that what you've measured at AC Input or was that calculated at one of these sites?!
 
[/QUOTE] What is your system specs then? i7 980X with 2x GTX580?
Also, that 800W, is that what you've measured at AC Input or was that calculated at one of these sites?![/QUOTE]

@Pada yes its running i7980x with 2GTX580's

No only tested with the site so far... Running a coolermaster 1200watt PSU.
How do you check the AC input?
 
Nokkie said:
@Pada yes its running i7980x with 2GTX580's

No only tested with the site so far... Running a coolermaster 1200watt PSU.
How do you check the AC input?
Click to expand...
Sweet rig :D Although I don't know what I'll do with something like that, seeing that my i7 940 + 2x GTX460 OC is already overboard... so I play all my games with everything maxed out.

I have a Voltcraft Energy Monitor 3000, which I used to measure the power consumption at the AC Input. You can usually measure it with an UPS too.
 
Thanks man, Didn't know that... ;)
Pada said:
Sweet rig :D Although I don't know what I'll do with something like that, seeing that my i7 940 + 2x GTX460 OC is already overboard... so I play all my games with everything maxed out.

I have a Voltcraft Energy Monitor 3000, which I used to measure the power consumption at the AC Input. You can usually measure it with an UPS too.
Click to expand...
 
Pada, they say up to 580W, does your rig draw up to 480W only? or just on average. :P Also I wouldn't ever listen to their recommendations seeing that they themselves are a PSU company you cant get more biased than that.
 
Nicko: my PC drew up to 480W, which was like the absolute maximum that my Energy Monitor device measured and kept as its maximum reading.
 
Pada said:
Nicko: my PC drew up to 480W, which was like the absolute maximum that my Energy Monitor device measured and kept as its maximum reading.
Click to expand...

Were all your HDDs running at max? Was your network maxed out? Was your sound card maxed? Etc etc. All these things would add to get you much closer to that 580W max load
 
Archer said:
Were all your HDDs running at max? Was your network maxed out? Was your sound card maxed? Etc etc. All these things would add to get you much closer to that 580W max load
Click to expand...
Nope. All of it wasn't maxed out. I ran Passmark BurnInTest & CoD4.
Even with my HDD + DVD-Drive + Network Card + Sound Card maxed out, I doubt that my PC would've used more than 520W.
I get your point that their calculated maximum might be almost on target, but in reality you will never stress all the components at once.
 
LOL Man did I overshoot!
I have a 1000w, turns out I only need 582w.
 
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