Power Supply Question

Hello all,

I recently built a new rig and was wondering if my Corsair 750 Watt Power Supply was going to be enough for a quick upgrade:

Currently:
AMD Phenom II X4 940 3.0GHZ Processor
ASUS M4A79 Deluxe Motherboard
8GB Mushkin DDR2 1066 RAM (4X2GB)
Coolmaster Hyper TX2 CPU Cooler
Antec 900 Gaming Case
Sapphire ATI Radeon HD 4870 1GB
Seagate Barracuda 250GB Hard Drive
(2) LG DVD Burners

I want to add:
Another Sapphire ATI Radeon HD 4870 1GB
Either HT OMEGA STRIKER 7.1 or CREATIVE sound blaster X-FI Xtremegamer 7.1 sound card
Another Case fan on side of case

Will the power supply I am currently using be enough for this system...I do not wish to overclock just yet I simply want my system to be stable, yet powerful

Michael

How do you monitor power supply useage cause i been wanting to figure out how to do that...also wanting to figure out if there is a power supply chart that shows what kind of components you have and how many watts you need.

Michael

Wow wish I woulda had that power supply calculator site before I built my system...

If I add another 4870 in crossfire and a nice soundcard I will be at 759 watts according to the results and I am using 750 watts...would be too much for my power supply?

Michael

+1 for what DellUser1 said.

The Corsair power supply is a high quality unit that earns high marks in technical reviews and comparisons. It is one of three or for brands that is often recommended by veteran posters at this forum. The 750 can handle your system

Two 4870 video cards operating in Crossfire mode use a combined total of 300 watts and 25 amps at full load.

The source of the information is the video card power requirements article here at Tom's hardware. The actual power usage chart is on page 6 of the article. You can find a link to the article on the home page of Tom's hardware. The rest of your components do not require anywhere near the power that the two video cards require.

It is the amperage on the 12 volt rail that you need to pay attention to. The Corsair 750 TX has a whopping 60 amps on the 12 volt rail. The two 4870 video cards only require 25 amps at full load. That leaves plenty of amps for the rest of the system.

The power supply calculators overestimate system power requirements because there are an awful lot of cheap, low quality psu's that people insist on buying.