PS calculators have very different answers.

[willmarth2]

I have the Antec True Power Trio TP3-550 550W ATX12V SLI Certified CrossFire Ready Active PFC Power Supply with Three 12V Rails. I want to add another 8800 GTS 640 mb card. Antec's calculator says I only need 430 watt PS. My MB website says 900 watts. Newegg's says 650. How likely would I fry my system with what I got?

 

[GhislainG]

You won't fry your system. Antec's PSU calculator assumes that you have one of their PSUs. Newegg don't know what PSU you'll use, therefore they can't take a chance. Your MB website can be ignored.

 

[JackNaylorPE]

MB site and newegg site is being overly conservative in case you buy a crappy PSU as well as providing their lawyers a cushion in case you try and blame them for something. Still make sure you include fans, all ya cards, all your external USb stuff, capacitor aging etc.

 

[willmarth2]

Best answer selected by willmarth2.

 

[willmarth2]

"capacitor aging"
My PS is 3 years old.

 

[JohnnyLucky]

I checked several technical reviews. The Nvidia GeForce 8800 GTS (512MB) isn't not a power hog. Luckily Tom's Hardware did a detailed article about how much power video cards need that included the 8800 GTS in SLI mode. The article included actual test results.

Below is a link to the actual power consumption charts. Please note all measurements are for total power draw at the wall outlet (mains). In other words it is total power consumption for the entire pc system. I think you'll find it interesting.

http://www.tomshardware.com/reviews/geforce-radeon-power,2122-6.html

Power supply calculators and video card manufacturers estimates and recommendations are just that and nothing else. Both are overestimated. There is a very good reason for that. Manufacturers know people will buy cheap, low budget, low quality power supplies of questionable performance and quality.

 

[Mousemonkey]

This topic has been closed by Mousemonkey