Is 18A on 12V enough?

[OBCT]

So, I bought this Rosewill 550W Modular Power Supply a few weeks ago, with 18A on the 12V rail. I'm now shopping for a graphics card, more than likely an X1900XT.

In particular, I like the HIS Hightech one with the non-stock cooler. According to its description on newegg, though, it says that it needs "30 Amps on 12 volt rail recommended."

Is it just me, or does that seem a bit exaggerated? Most PSUs that I looked at had 20A or less on the 12V rail, and only two met HIS's recommendation. Will I be fine with my power supply, or should I start looking for a new one? (Maybe use the Rosewill as backup?)

 

[sisq0kidd]

I strongly recommend a new psu as 18A will not be enough under full load for the x1900xt. You might experience some shutdowns or restarts.

30A is overestimating the requirements to run that x1900xt, but better safe than sorry.

But I guess in the end, just test it out first to see if it can handle it.

Edit:

Looking at the psu again, the 12v is split into two 18A parts. So you have dual 12v rails. You should be fine.

 

[postmortemIA]

I had 26A 12V high quiality PSU (Antec TruPower), and that was not enough for my 6800 ultra. But it worked fine on dual 12V rail PSU, that had 19A on each 12V rail.

Same applies to your rosewill PSU - it has dual 12V rail, so it will work, as the actual number is 18*2=36A.

And i would invest 10$ and get Antec TruPower 550W, Rosewill is generic brand.

 

[Avalon]

Originally posted by: postmortemIA
I had 26A 12V high quiality PSU (Antec TruPower), and that was not enough for my 6800 ultra. But it worked fine on dual 12V rail PSU, that had 19A on each 12V rail.

Same applies to your rosewill PSU - it has dual 12V rail, so it will work, as the actual number is 18*2=36A.

And i would invest 10$ and get Antec TruPower 550W, Rosewill is generic brand.

Two 18A rails do not equal 36A.

 

[morgash]

i have a e-power cheetah 470watt that has one 28A 12V rail and it runs my system perfectly.

x2 3800+ @ 2.8ghz
2gb DDR 500 G.Skill 2-3-3-6
x1900xt @ 700/800
80gb WD and 320gb WD
Audigy 2 ZS
TT Big Water 745 Water cooling kit with CPU and GPU in the loop.

All depends on the quality of the PSU and after using this one for the past 2 years now i can say i love it

Morgash

 

[OBCT]

Alright. Sounds like I shouldn't need to worry about finding a new psu. Not for a while anyway. Next time I need one, I'll definitely pay more attention to specs like these.

 

[LOUISSSSS]

NO its not enough

 

[akshayt]

Will Antec NeoHE 500 be able to power my system after huge cpu and ram overclocks.
It has 3 X 17A 12VA rails and a total of 38A.

Also r1+r2!=(r1+r2)amps

antec sp 500 has i think 17A + 19A = 36A but a max output of 25A on 12VA @ 25C !

doesn't 1900xt/xtx need around 20A on the 12VA line alone?