ATI X1950XTX PSU

[SunnyD]

I just received my new ATI X1950XTX video card, and in looking it over, there's a little sheet packed in with it with the following exact text:

Power supplies with 450-watt capacity and 30A on 12V rail is recommended for single Radeon X1900 series product.

Now I know I need a new power supply, since mine doesn't even have the PCIe connector on it... but what confuses me is that it's asking for a 450 watt PSU that has a 30 amp 12V rail. I looked at a fair number of PSU's, and frankly, NO 450 watt PSU's hit 30 amps on a single 12V rail. What gives?

 

[Qbah]

Check the maximum power output of the 12V lines (the producer usually states it) and divide it by 12. You'll get max amps the 12V can provide

 

[TanisHalfElven]

a single rail can only provide max 20 amp due to saftety reason.
mobo's with more usually have dual 12V rails

 

[akshayt]

a 1900XT/XTX needs 10-11 amps or so on the 12V line. 30A is the recommended option for the whole system together.

 

[BFG10K]

Now I know I need a new power supply, since mine doesn't even have the PCIe connector on it...

That's what the splitter is for and it's usually included with the card.

 

[SunnyD]

Originally posted by: BFG10K

Now I know I need a new power supply, since mine doesn't even have the PCIe connector on it...

That's what the splitter is for and it's usually included with the card.

Odd, since mine didn't have one in the box. I'll check again though.

 

[jiffylube1024]

Originally posted by: SunnyD
I just received my new ATI X1950XTX video card, and in looking it over, there's a little sheet packed in with it with the following exact text:

Power supplies with 450-watt capacity and 30A on 12V rail is recommended for single Radeon X1900 series product.

Now I know I need a new power supply, since mine doesn't even have the PCIe connector on it... but what confuses me is that it's asking for a 450 watt PSU that has a 30 amp 12V rail. I looked at a fair number of PSU's, and frankly, NO 450 watt PSU's hit 30 amps on a single 12V rail. What gives?

That's the combined +12V power. Typical power supplies these days are dual rail (Antec goes overboard by using 3 rails even down to 400W [3 rails is excessive on PSU's under ~550W]).

What you need to look for is combined +12V power of 30A (which is most 400W PSU's and above if it's of high quality).
Here's a good example from the Enermax Liberty 400W (click the fourth picture where it shows the rating).

You can clearly see: +12V1 = 20A, +12V2 = 20A and combined is 360W (30A). Most companies don't calculate the amps for you on the combined rail but make you do the calculation yourself (just divide the wattage by 12). They do this because 2X 20A sounds more impressive than '30A combined.'

---------------

Typical Antec/Enermax/OCZ Power supplies 450W and up will be fine.

You don't just add the two +12V rails, but pretty much anything with 18A on each +12V rail will give you 28-30A combined, which is more than enough power for that card.

The '30A required on the +12V rail' is a catch-all because many lower quality PSU's are rated for mid to high 20A on the +12V rail, but they can't deliver it sustained. A good quality PSU at 26-28A +12V will serve that card fine.

With that said, I would personally get something like an Enermax Liberty 500W, or the new Enermax FMA II 535W (the one I use, it's great). Other excellent powersupplies are the Antec TruePower 2.0 550W or (even better) Neo Power 550W. OCZ 520W Powerstream is great, and OCZ GameXStream PSU's (500W, 600W, 700W) are good too.