How accurate are power supply calculators?

[TP-Oreilly]

Hi, i have a 520w coolermaster psu, i want to add another card to my system, i used a power supply calculator to check if my psu could handle it, with it i ticked all the stuff my system has plus gpu's in crossfire seeing as i want to add another one and it came out saying it RECOMMENDS having a 519w power supply, would i be ok in getting another one then.

Here is the link to the calculator, Antec Power Supply Calculator

I told it i wanted to use two 5830 ati gpu's, but i am only gonna use one of those and the other will not be as power demanding.

??

 

[Indigo]

What will the other one be?

In most cases, these power supply calculators are pretty accurate, though ones from a vendor (in this case, Antec) will be weighted to side on the power heavy side so that you buy an upgrade.

That being said, the Antec one you just linked is amazingly accurate for what it is. I'm adding that one to my favorites (thanks!)

Depending on usage, and what your other card is, my knowledge and experience says as long as it's not another video card, or at least, a low powered video card, you should be fine. full system specs though would help us gauge your needs better.

 

[TP-Oreilly]

i have :

i7 930
hd 5830
3gb of ocz ddr3 1600mhz ram
GA-X58A-UD3R
corsair f60 ssd
80gb hard drive
cv/dvd drive
5 fans
CM 520w psu

The card im thinking of adding is a geforce 450, to use as a dedicated physx card, i believe this only needs on 6 pin power cable

 

[Indigo]

physx is a gimmick. Turn it on and you get more particles, debris and crap that don't need to clutter up a good game. There's no real benefit to using it on a system other than to guzzle power or waste your money. It MIGHT be more useful in 3D modeling, but I've yet to see a real benefit to it.

That being said, I'd upgrade to at least a 600 watt power supply if you put the card in your system, just to be on the safe side. One of the Thermaltake or Corsair 600's should be fine.

 

[Aastii]

physx is a gimmick. Turn it on and you get more particles, debris and crap that don't need to clutter up a good game. There's no real benefit to using it on a system other than to guzzle power or waste your money. It MIGHT be more useful in 3D modeling, but I've yet to see a real benefit to it.

That being said, I'd upgrade to at least a 600 watt power supply if you put the card in your system, just to be on the safe side. One of the Thermaltake or Corsair 600's should be fine.

I have a difference of opinion about Physx, but only if OP will be playing Physx games.

On topic though, I have a difference of opinion about the power supply recommendations as well. With the exception of the toughpower units, Thermaltake units are nowhere near the levels of quality that other units are. Corsair however I agree with, but they tend to be more expensive than other units, except for the CX430, but only because they crapped out on quality compared to the CX400 units, unless they have rebates of other offers on.

Corsair, Antec, XFX, SeaSonic, Be Quiet!, Enermax and Silverstone are all brands I would recommend using

 

[Indigo]

Corsair was Seasonic, Thermaltake was PSH. Both reputable in their own right. I'm more leery of Thermaltake than I am of Corsair, but that's only because I have used Corsair a lot lately.