x1900Xt Power consumption?

paul1980 · 15 Mar 2006 at 16:56

Hi,

At the moment I have a AKASA Paxpower 400W PSU. If I decide to upgrade to a X1900XT will this power supply do?

I currently have the system shown below. (Obviously I would need PCI-E mobo too).

I only have 1 HDD and 1 DVD writer etc so no real extras that take power.

Datamonkey · 15 Mar 2006 at 17:06

mate im praying my shuttle 350watt will run it, but from reading up the shuttle psu's are of a lot higher quality, so tomorrow eve i will be able to tell ya lol.

easyrider · 15 Mar 2006 at 17:11

they draw 50% more power than an 7900 GTX I would have thought it would be ok but not defo.

xknight2000 · 15 Mar 2006 at 17:13

Would a 550w be ok do you think?

easyrider · 15 Mar 2006 at 17:14

xknight2000 said:
Would a 550w be ok do you think?

would have thought so

xknight2000 · 15 Mar 2006 at 17:14

What about for Crossfire?

easyrider · 15 Mar 2006 at 17:17

xknight2000 said:
What about for Crossfire?

nuclear power station!

not sure tbh

fornowagain · 15 Mar 2006 at 19:21

xknight2000 said:
Would a 550w be ok do you think?

ATI recommends a 450W power supply with a 30A 12V rail for a single X1900XTX or a 550W part with at least 38A for the 12V rail for Crossfire.

Ignore the wattage it's meaningless. It's the current available on each 12v rail. This article may help.

fullfat · 15 Mar 2006 at 19:51

so what happend if youre psu has a dual 12v rail? as mine is rated at 18a :confused:

chaparral · 15 Mar 2006 at 19:54

fullfat said:
so what happend if youre psu has a dual 12v rail? as mine is rated at 18a

Mine rated at 17a and i been runining my x1900xt-x at 690/800 with no problems for about the last 5 or 6 weeks..

fullfat · 15 Mar 2006 at 20:08

hmm, my psu doesnt have the 2 12v thing on it but it says on the antec website it is a dual rail psu (neopower 480w)

fornowagain · 15 Mar 2006 at 20:32

chaparral said:
Mine rated at 17a and i been runining my x1900xt-x at 690/800 with no problems for about the last 5 or 6 weeks..

That's a shuttle PSU if I'm not mistaken, which are well known to be under rated. Even SLI shouldn't be a problem with a 350w shuttle PSU from the reports I've seen. 17A is more than enough for a single card as long as that's all that's pulling current on that rail. An XTX will pull 12/13A full load. A normal 400W ATX is going to struggle.

Antx777 · 16 Mar 2006 at 00:41

Well, I've just read some of that article Fornowagain, and I now have a Seasonic 600 - and this "passed" the test in the article above mentioned. I am "only" on a ATI X850XT - but run 3DMark 2006 - at full AA/AF settings etc, and no issues here. Does 18 Amps on each rail (which mine has) give a true 36 Amp total then?

Originally posted by chaparral
Mine rated at 17a and I been running my x1900xt-x at 690/800 with no problems for about the last 5 or 6 weeks..

I would upgrade that if I was you. I had a FSP 300 watt PSU before my seasonic, and that had 18 amp on the rail. It blew (very loudly) when I was playing F.E.A.R. Best never to skimp on PSU's

Anthony

fornowagain · 16 Mar 2006 at 00:51

Antx777 said:
Does 18 Amps on each rail (which mine has) give a true 36 Amp total then?

No not always, it doesn't. Both rails are normally fed from the same AC/DC bridge, tranformers taps etc. Look at the spec on the PSU itself, it should give you a combined 12v current. Same goes for 5v/3.3v normal spec is single but they are fed from the same rectification circuit. When it says 12v1 18a, it means 18a maximum when nothing else is drawing from same feed. Two 18A is going to supply something like 30A approx total.

Wait up, I'll have a look. 12v is 432w max = 36A which is very good. But it is a max figure so take about 85% for a sustained draw.

Monstermunch · 16 Mar 2006 at 00:51

Just thought i'd chip in and say that I sent an email to ATI a few weeks ago posing a similar question regarding recommended PSU wattage. They replied about a week later saying that they recommend 400W minimum for X1800/1900 series cards and 500w minimum for Xfired cards.

Booner! · 16 Mar 2006 at 00:52

i read good things about the FSP , about to buy the 600watt

, i reackon that you had too low wattage, i.e 300watt wasnt obviously enough, i never go below 450watt and have been fine, good 12v rail helps ( i have tagan currently)

fornowagain · 16 Mar 2006 at 01:09

Booner! said:
i read good things about the FSP , about to buy the 600watt , i reackon that you had too low wattage, i.e 300watt wasnt obviously enough, i never go below 450watt and have been fine, good 12v rail helps ( i have tagan currently)

Its Fortron IIRC good make and they also supply Tagan IIRC. I've been suggesting the 60A combined one for awhile, hoping someone would buy it and report back.

The best way to see if the PSU is limpingis is to connect a multimeter to one of the molex and run 3dmark06. If the 12v drops more than 5% (3% is to much in my book) then its either rubbish or your pulling to much current. Either way get a better supply. Don't believe monitor programs.

turbotoaster · 16 Mar 2006 at 04:15

ive got a tagan 580w on my xfire setup which is fine running at stock, but when ya overclock the cards, it draws to much amps and the computer shuts down, they are 20A per rail as well and it seems that its not enough, so gonna run 2 psu one for cards and another for everything else and well see what happens

Datamonkey · 16 Mar 2006 at 08:19

Its at this point im going to say,

Graphics cards are getting to the stage where its getting silly re psu requirements, we imho need to start seeing graphics cards with external power solutions. I for one wouldnt be bothered by this.

I think its the best route forward, what ya think?

fornowagain · 16 Mar 2006 at 13:29

I think buy a decent PSU. I have a PCPower&Cooling 510 and the rails are so solid that the monitor programs show a straight line even when loaded. The variance is less than 1%. Trouble is, they cost twice your average.