Psu and sli setup

So I'm trying to figure out if my psu is going to be able to handle an sli setup. The whole split rail/amperage thing is kind of confusing to me so I'm not entirely sure if I'm going to need a new psu.

My current system consists of:

Core 2 Quad Q6600
2 sticks of 2048mb pc6400 ddr2
XFX 680i LT mobo
1 optical drive
EVGA 8800gt video card

Nothing in the system is oc'd.

I want to add a second 8800gt to my setup and was wondering if my psu will be able to handle this. I'm currently using a Xion powerreal 600w. Here is the link to the psu:

Now the psu says it only has a 22a rating on the 12v rail and the 8800gt says it requires a minimum of 26a. Currently my system is running fine with the single 8800gt.

I know that overall wattage isn't as important as the amp rating but I ran the numbers through a couple of the wattage calculators online and it averaged around 442w. The psu can handle around a 550w continuous load so I'm not really concerned about that.

I couldn't find anything about whether or not the psu had a limiter on the 12v rails or if it would share the amperage across the 2 so if anyone has any idea I'd appreciate an answer.
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  1. Actually that PSU has 2 12v rails each with 22a for a total of 44a. Thats not a totally junk power supply but I would not try running SLI on it.

    I would recommend a Corsair or a if you think you might go bigger than the 8800GTs someday and want some room to upgrade.
  2. I really doubt that PSU can output 44A. The first clue is that it fails to tell you total output for the 12v1 and 12v2 underneath the chart. All good PSUs will tell you. Bad PSUs like this will try to hide it. The second clue is the heavy 5V rail. What good modern PSU can output over 50A on the 5V rail? Another clue is the voltage select switch in the back. These three things together tell me that its an older design, and won't do anywhere near 44A. Build quality is also probably pretty bad, here is a review of the same series unit but at 700W instead of 600.

    Your better off buying a new PSU and video card. Two 8800GTs are good, but pale to newer cards.
  3. XION is not a brand with a reputation for high quality power supplies.

    The general rule of thumb is a high quality 500 to 550 watt power supply with sufficient current (amps) on the 12 volt rail(s) can easily power a system with any single video card made. A high quality 700 to 750 watt power supply with sufficient current (amps) on the 12 volt rail(s) can power a system with two video cards operating in dual mode. There are a few exceptions like the new ATI Radeon HD 5000 series cards which use less power due to their energy efficiency.

    A high quality 500 to 550 watt psu will have a +12 volt rail rated at 40 amps. A high quality 700 to 750 watt psu will have a +12 volt rail rated at 60 amps.

    In addition the power supply should be at least 80+ Bronze certified for energy efficiency.

    Corsair, PC Power & Cooling, and Seasonic are some of the brands that have a reputation for high quality power supplies that consistently earn high marks in technical reviews. They are reliable, stable, and come with a 5 year warranty. Some of the newer models come with a 7 year warranty. Lately we've been seeing a few other brands offering some high quality units. An example would be the Antec Earthwatts series which is an improvement over Antec’s older series such as the Basiq models.
  4. Oops, forgot the link.

    Group regulated, never hit 80% efficient, high ripple, exhaust temp high enough to roast wienies, etc. I wouldn't trust this to any setup. Don't forget about this gem on page 1

    There's a third missing bit of information up there, namely the lack of a UL file number under that backwards "UR" logo. We're going to have to go by clues inside the unit as to the actual OEM. But I'll tell you who it is already, no need to wait for page three: Superflower.

    Its not even UL certified.
  5. Thanks all for the responses. Looks like I may just buy myself a new psu before I try and hook up my second card. I'd rather be safe than damage anything.
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