Xfire 5770 PSU question.

hamiac

Distinguished
Feb 22, 2010
117
0
18,690
Although 5770s are knowen to be quite efficient, you will find most graphics card manufactures will recomend a 650W powersupply for Xfire. I hear they do take a big load when they boot up.
I am building a 5770 system too (just one 5770 for now) but just incase I go Xfire I have bought a Corsair HX650.

So I would recomend upgrading if you want to go Xfire
 

JerseyDevil101

Distinguished
Feb 24, 2010
45
0
18,530
Hmm.. if I do plan on buying another video card will my pc boot up if the wattage is too low or will my pc just freeze up and everything if i turn it on with xfire?
Ohh and i think my sig. should work now

Thanks guys
 

JerseyDevil101

Distinguished
Feb 24, 2010
45
0
18,530
So I really shouldn't go by the Antec website on how much wattage you will need to power up your system... Hmm maybe I should return my PSU and get one with like at least 650 watts of power.
 

moody89

Distinguished
Oct 6, 2009
799
0
19,160
On the Sapphire website, your GPU is rated at a max. board power of 108W. I'm assuming that to have 2 of these exact same cards would be 216W max. So depending on what else is in your computer I would go by that. I'm not sure if the Amps on each rail has any bearing on this; I'm not really an expert on PSUs. Hope this helps a bit though!
 

hamiac

Distinguished
Feb 22, 2010
117
0
18,690
If you follow their recomendation you are garanteed that you will be ok (as long as it is a true 650W), anything under that just hope that it will work. A bigger PSU at low load will run cooler than a small PSU at high load, so a couple of advantages
 

JerseyDevil101

Distinguished
Feb 24, 2010
45
0
18,530
Antec recommended a 750 Watt PSU for the crossfire of two 5770 graphics cards which is reasonable. Idk whether I should take the PSU back that I have now and get a higher PSU or wait till higher end graphics cards come down in price a bit. If I want to upgrade in the future.
 

hamiac

Distinguished
Feb 22, 2010
117
0
18,690
Wow, 750 watt!!

Surely you shouldnt need that much. That could be saying their PSUs will not provide a true 600 watts or what ever it was that the cards need. I think a top quality 650 watt PSU should do fine really.

Have a look anyway
 
First, The Antec power supply you linked to is an older Basiq model. It may be adequate for average use but it is by no means a stellar performer. Antec has newer and improved power supplies such as the Earthwatts models.

Second, you mentioned the ATI Radeon HD 5770 video card in Crossfire mode. Here are the ATI recommended power supply requirements for the ATI Radeon HD 5770 and 5750 video cards:


450 Watt or greater power supply with one 75 watt, 6-pin PCI Express® power connector recommended

600 Watt or greater power supply with two 75 watt, 6-pin PCI Express® power connectors for ATI CrossFireX™ technology in dual mode.

The recommendations are for an entire pc system..

Corsair and Seasonic are two of the brands that have a reputation for high quality power supplies that consistently earn high marks in technical reviews. They are reliable, stable, and come with a 5 year warranty. Some of the newer models come with a 7 year warranty. Lately we've been seeing a few other brands offering some high quality units. One example would be the Antec Earthwatts series which is a major improvement over Antec’s older psu’s like the Basiq models.