55 amps is 55 amps. One or more rails - it shouldn't matter.
I can't confirm that PSU can actually provice 55 amps of +12V. There isn't enough data on the data plate to be sure. You can't just add up each +12V rail - you have to known the max +12v the PSU can actually produce.
For comparison here is the Corsair 750TX data plate (and it happens to be less expensive):
April 12, 2009 3:33:58 PM
So the corsair TX750 will do GTX 280 SLI without shortening its life.
Is it better to get a used Enermax Galaxy 1000w for 70$ more?
It has 76amps from 5 rails(900w on the 12v) but I am picky because it is used and its performance may degrade.
Corsair > Enermax. If you really want 1000W, go for the Corsair HX1000. I have one of those and it's awesome. But really, unless you're SLIing dual-gpu cards, or going for tri-SLI+physics, there's not much point to a 1000W. Something like the TX750 would be fine.
As a rule I never buy 2nd hand PSUs, you never know how long they've been running, how much load they've been under, what conditions they've been exposed to, etc. etc. etc.
April 12, 2009 4:14:18 PM
Ok, so now thers the TX850(70amps) and the TX750(60amps). The price difference is 20$.