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Im going to be upgrading my graphics card in the next week or two but Im concerned after seeing this http://www.tweaktown.com/articles/11...sts/index.html that my psu might not be up to it. I have a 500w psu and am currently running an X2 6000 at stock, 2gig DDR2, x1950 pro, 2 x hard drivers sata, 2 x sata DVD-RW's.
What are the min psu requirements for the above cards or do you think I will be ok?
thanks.
I think you'll be fine.
If you want a more quantitative opinion, try this:
http://www.extreme.outervision.com/psucalculator.jsp
Great, thanks for that. According to that, with a 2900XT it recommends using a 415w psu so it looks like I'm good to go :)
The problem with graphics cards and pwoer tend to come not from the total wattage but the +12v rail
You should be ok with the Great power or Stable power series, however you might have a problem if it's the Good power series.
From the Xclio web site the good power has 2 +12v rails rated at 16a and 17a, but a total combined max ampage/wattage on the +12v is not listed.
You could check the sticker on the side and see if it gives a combined +12v max, (if it's in watts then devide by 12 to get amps)
only way is get a new card an try.
hey guys.... i definately wouldnt think that PSU is fine...!
For a 1950pro you need to have a sustained rating of at least 30a on the 12v rail
34a if its a multi rail unit!
I have a 1950pro on a 500watt generic psu... (it had 18a max on the 12v rail... and the card worked fine for a few days then sent my monitor into standby mode!)
I upgraded to an OCZ GameXstream 600W which ran it fine... infact i couldve ran two of them no hassles. ( 4 rails with 18a max on each - something like 50a total output sustained)
This new HD2900 is a beast! its much bigger, heavier and has a helluva lot more processing power... its power requirements are definately higher aswell!
I was gonna get two and crossfire them, and then I realised that I would need at least a 750W with 50a sustained to run them with my quad with no hassles.
I opted for one only and an Enermax Galaxy 1000W PSU... will get the 2nd card to crossfire next month when I have more cash.
I know its tempting to think, perhaps itll run... but youll end up killing that power supply, perhaps blowing your ram / cpu / card / motherboard aswell when it goes down and an underpowered system will run a lot hotter!
When I had the X1950pro on the generic 500w psu, it idled at 65.... on the OCZ 600W it idles at 40... big diffs...
Get the right power before you get the card and youll have no issues atall... get the card first and youll have endless crap till you finally buy the right power.
Well, it's true that you need a lot of power to run a high-end graphics card, but you'd have to have a particularly awful 500W PSU for it to only be able to provide just over 200 Watts @ 12 volts.
I'd advise you check to be on the safe side Slinger, but in general people just do not need as much power as they think. I'm yet to see my system ( <<-- See over there ) exceed 300 Watts power usage at the wall socket.
With high end graphics cards, especially the ATI ones, Wattage is not as important as amperage... its Amps that they need...
if you have a 600w 18a power supply... and a 400w 30a power supply... the 400w will run the card and the 600 will struggle and overvolt itself trying to keep up with the demand...
Wattage isnt important when dealing with high end cards.
amperage is.
Dude, I think you need to sort your physics out a bit... although I understand what you are trying to say.Quote:
Originally Posted by twicksisted
I was referring to Watts@12 volts. Specifying Watts at a certain voltage is basically the same as talking about amps.
Your example was of a 500 Watt (overall) PSU you'd owned that could only provide 18 amps @ 12 volts = 216 Watts @ 12 volts. That must have been a particularly shocking example of a 500 Watt PSU, because god only knows why you'd want the other ~300 Watts spread over the other voltage rails (presuming there was only a single +12V rail).
Or not, because the maximum rated amps over a single 12V line for ATX2.something is only 18A. Thus all ATX compliant PSUs should only provide 18A per 12V rail.Quote:
Originally Posted by Fraz
Luckily most manufacturers are breaking this.
Sigh.
So you don't think that a 500 Watt PSU providing only 18A on a single 12V rail is not a very poor example of a 500 Watt PSU?!
I bet you wouldn't buy one.
Back on topic for the original poster, hopefully this discussion should make you want to check the sticker on your PSU. See what it can provide in terms of current (or power) at various voltages... post up the result here.
I wouldn't. 18a on a 500w PSU sounds pants, I'd expect 30a upwards on a good 500w psuQuote:
Originally Posted by Fraz
I would grab one of these from this official certified ATI list, as it will give you headroom in future to expand and will run your card without issues:
http://ati.de/technology/crossfire/buildyourown2.html
And another thing, all PSU's have different Amperage values on their rails, even if they are supposedly the same wattage as other makes. This is what seperates the good from the bad. just remember that the values show are always the "Maximum" values for that one rail alone and not combined "sustained" reading of all rails at once.
you need at least 30A sustained on a single rail unit, and 34a on a multirail unit.. to run that card without risking damaging it and the rest of your system somewhere along the line.
Thanks for all the replies guys :) I've checked the psu and its a 480w with 2 x 12v rails providing 18a on each but it says 33 max in brackets :O_o1: However, I have bought a new psu, a PC Power & Cooling 510w real (650w peak) psu for £45 delivered so I should be covered now anyway I hope :)
thanks for the advice.