Sign in with
Sign up | Sign in
Your question

Which graphics card is limit with my PSU

Last response: in Graphics & Displays
October 16, 2012 4:46:27 PM

I have QDION QD-450 PSU
It's made by FSP but without FSP quality, something betwwen cheap china PSU's and normal FSP :) 
It's stock PSU from Asus Vento case.

+3.3v 24A
+5v 23A
+12v1 17A
+12v2 15A
+5vsb 2.5A
-12v 0.5A

Core i3-2100
2 DDR3 4GB
USB keyboard and mouse
No dvd

I'm looking to buy some used videocard, probably radeon 6 or 7 series or nvidia gtx4XX or gtx5XX.
Which videocard is limit for this PSU , something like HD6870/gtx560?
October 16, 2012 4:57:53 PM

I need the total PSU wattage.
October 16, 2012 5:04:46 PM

Related resources
a b U Graphics card
October 16, 2012 5:15:33 PM

I recommend getting another power supply before upgrading your video card. Many cheap power supplies don't put out their stated wattage. Does it have a gpu six pin power connector? What are the specs of the rest of your system?
October 16, 2012 5:31:08 PM

Yep,it has 6pin connector
As for specs, check first post
October 16, 2012 9:11:16 PM

The best you can safety get with your current power supply is GeForce GT 640, and that is still dangerously pushing it.
a b U Graphics card
October 16, 2012 9:26:11 PM

the most important thing in psu beside real wattage or not is the psu ripple and rail stability..

cheap psu usually (well, i mean "always") give a huge ripple and bad rail voltage when you push it even at 50% power..

it's the main reason why cheap psu can damage your component..

well, i agree with mr. maestro and mr. pepto...

before you thinking to change your graphics card to the higher level, change your psu first..
a b U Graphics card
October 16, 2012 10:18:44 PM

doing a little math and some guessing:
adding up those rails 3.3, 5 and 12 volt) gives you the total of ~580 watts (i think that is what i got but i cleared my calculator) which is ~128% of 450 watts; in other words 28% more. so even though each rail may be rated at those amps that is not what it can supply combined.

so removing 28% of 12V2 (which the pci connection would be on) (12*15)/1.28=140.625 watts. keeping that at 80% 140.625*.8= 112.5 watts. chances are your sata power is sharing the same rail so remove 10 watts for the hard drives. (spinning up they'll use 10 each but will use half that after boot up)

102 watts rounded down. without knowing the actually quality of the PSU; that is the best i would expect to be available for a graphics card.

now those are stock non overclocked reference cards. you are talking about a 5770/7770/650ti range to be relatively comfortable. maybe a 7850/6850/450

but that is selling your i3 2100 a little short; getting a better PSU, even a 450 watt one that is better quality will get you a 7850 easily and the prospect of a 660/7870 card.
a b U Graphics card
October 16, 2012 10:31:46 PM

If your intrested in a really cheap PSU upgrade this is the way to go:
you could probably get away with running up to a 7770 on that PSU, but pushing your PSU isn't good so I wouldn't recommend going higher than say a 7750 on it.

If you want to spend some more money and get one that will handle future upgrades or a better card right away this is a good way to go:
I believe that my PSU, XFX core edition, is pretty much the same thing mine just has more power (like I said, buying more than you need for future upgrades is a good thing) the point being that I like my PSU and it's been good so far.
October 17, 2012 2:16:23 PM

Thanks for help