What psu should i use?

[kiralyka]

I have a big problem cause i want to buy a new vga but dont wanna a new psu so can i run Hd4890 with 450w psu or need a bigger one?

 

[nate42nd]

They recommend 500W. My guess is 450 will be okay. If you are running 2 HDs or 2 DVDs I would think twice. I did the same thing with a card, I am running 50W under the specs and it runs fine.

 

[smarteyeball]

It depends on wheter it's a quality PSU or a generic one.

If it's quality and you don't have too many other devices etc, you'll be pushing it, but it should be fine.

However if it's a cheap generic PSU.......NOT recommended.

, I am running 50W under the specs and it runs fine.

....and it probably will until it all goes FFZZT

 

[kiralyka]

i have 2 hd-s and 1 dvd and a few usb accesories and my psu is a chieftec smart 450

 

[torrentg]

You'll be alright with that. My ATI card recommends 450W. I'm on 350W psu with 4 HDD, 1 DVD, Firewire powered audio, and like 6 USB peripherals.

 

[kiralyka]

Th guys for help...

Im upgradeing and still the psu is the main q.
Should i buy a bigger (550w from asus) or stay with this one?
Oh and i would like to run 2 4850s in cf i know it sound a little stupid but hey its crisis in the world...

 

[bobkn]

I think that the Chieftec may be a little weak. I see that it's rated at 14 and 15A on its two +12V rails.

ATI certifies PSUs:

ATI CrossFireX™ | GAME.AMD.COM

(It's a Crossfire site, but it covers single cards as well.) The lowest power supply certified for a single HD4890 is a 500W Zalman unit with two 18A +12V rails.

Your Chieftec unit wouldn't be on the list, even if it was adequate, because it has a single PCI-E connector. (You need two 6 pin ones. You might be able to get away with the molex-to-PCI-E adapter that most cards include.)

If you want CrossfireX, at current prices, I'd suggest two 4870s in SLI rather than 4850s. However, you'd need *four* PCI-E connectors. This one would work:

Newegg.com - PC Power & Cooling S75CF 750W EPS12V SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Power Supplies

(PC Power & Cooling Silencer 750 Crossfire, in ATI Red.) I've run a pair of 4870s with one. (It's rated at 60A on its *single* +12V rail.)

 

[kiralyka]

Thanks I will buy a bigger.