Quad-core + 2x5770 Xfire is 550watt enough?

[tacoma08]

Hi everyone

My current setup:
Q9300 @ 2.5 (stock no OC)
6Gigs ddr2 ram
Asus Pq5 Pro Turbo
His HD Radeon 5770 Iceq5 Turbo (920/1300)
OCZ Fatla1ty 550watt PSU
Radidmax Smilodon Extreme Black Case (2x80mm 2x 120mm fans)
WD 640gig HDD @7200
Sata DVD+R/RW Multi Drive (Not Bluray)

This is the Power supply in question.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817341022&cm_re=ocz_fatal1ty-_-17-341-022-_-Product

it cost more than some of the 600-700 watt psu's i ws looking at but it seemed to get really good reviews and seemed like a high quality psu. its got 2 12v rails @ 25amps. I think the 5770 only needs 18amps (i think)

I looked up the power consumption of the 5770 xfired on i7 systems which are more power hungry and they seemed to be around 320-380 not reaching 400watts. At max load it uses 108, and my cpu at max load is rated at 95. Thats 311watts minus the mobo ram dvd and hdd. Oh and fans.

So ive decided to ask the PSU gurus here on TH if my 550 can handle 2 5770's. Or will it explode and take my whole system with it?

 

[WR2]

Hi Tacoma08;

I think the 5770 only needs 18amps (i think)

That sounds about right but it's 18Amps +12V = 216watts for the entire system... not just the video card. Your OCZ PSU has 450W of +12V which works out to 37.5Amps in total.

The HIS website (5770 IceQ 5 Turbo 1GB) recommends "450 Watt or greater power supply with one 75W 6-pin PCI Express® power connectors recommended (600 Watt and two 6-pin connectors for ATI CrossFireXTM technology in dual mode)". And that would be an 'average' 600W PSU. Your 550W OCZ is 'above average' - so I think you're in good shape to go ahead and run 2.

 

[tacoma08]

Hi Tacoma08;
That sounds about right but it's 18Amps +12V = 216watts for the entire system... not just the video card. Your OCZ PSU has 450W of +12V which works out to 37.5Amps in total.

The HIS website (5770 IceQ 5 Turbo 1GB) recommends "450 Watt or greater power supply with one 75W 6-pin PCI Express® power connectors recommended (600 Watt and two 6-pin connectors for ATI CrossFireXTM technology in dual mode)". And that would be an 'average' 600W PSU. Your 550W OCZ is 'above average' - so I think you're in good shape to go ahead and run 2.

Awesome! Just the answer i was looking for!

Now just one more thing, does overclocking significantly increase power consumption or just a little bit? I plan on oc'ing the second card to 920/1300 as well, and to make sure my cpu doesn't bottleneck i was gonna do a light oc from 2.5 to 2.8ish. Would the 550 still be enough?

 

[faune]

Well here are the official recommendations:

450 Watt or greater power supply with one 75W 6-pin PCI Express® power connectors recommended (600 Watt and two 6-pin connectors for ATI CrossFireX™ technology in dual mode)

My Gigabyte HD 5770 states the following regarding the 12v rail for a single GPU: "Minimum 450 w PSU with a 12v current rating of 24A"

I punched in your set up in Xfire mode (2 x 5770) into the PSU calculator and got ~ 370W. This estimate btw, is with out knowing how many usb devices you have pugged in and how man sticks of ddr2 ram you have. I guessed two but even four sticks doesn't make that big of a difference, ditto with usb devices.

PSU calculator: http://extreme.outervision.com/psucalculatorlite.jsp

Try it yourself...

In any event maybe someone here can tell you if it will work for just to make it 100% sure.

 

[faune]

+1^ for WR2

beat me to it as i was writing my post

 

[tacoma08]

Well here are the official recommendations:

450 Watt or greater power supply with one 75W 6-pin PCI Express® power connectors recommended (600 Watt and two 6-pin connectors for ATI CrossFireX™ technology in dual mode)

My Gigabyte HD 5770 states the following regarding the 12v rail for a single GPU: "Minimum 450 w PSU with a 12v current rating of 24A"

http://i985.photobucket.com/albums/ae333/Faune1/IMG_2548.jpg

I punched in your set up in Xfire mode (2 x 5770) into the PSU calculator and got ~ 370W. This estimate btw, is with out knowing how many usb devices you have pugged in and how man sticks of ddr2 ram you have. I guessed two but even four sticks doesn't make that big of a difference, ditto with usb devices.

PSU calculator: http://extreme.outervision.com/PSUEngine

Try it yourself...

In any event maybe someone here can tell you if it will work for just to make it 100% sure.

Cool, thanks for the link! My total output at 90% with all my fans was 379 Sweet! Im gonna go ahead and combine that data with what WR2 said and assume i can do crossfire and not have to buy a new psu! Woohoo!

Thanks everyone!

 

[tacoma08]

Best answer selected by Tacoma08.

 

[WR2]

Now just one more thing, does overclocking significantly increase power consumption or just a little bit?

That 2.5Ghz to 2.8Ghz would fall into the 'little bit' category I would think. You should be OK there as well, even with the dual GPU overclock.

 

[tacoma08]

That 2.5Ghz to 2.8Ghz would fall into the 'little bit' category I would think. You should be OK there as well, even with the dual GPU overclock.

Awesome thanks! I was thinking that too but wanted to make sure 100% since ima noob at oc and have never overclocked before. (which is why im going for the small 2.8 oc)

Thanks for the help, appreciate it!

 

[Mousemonkey]

This topic has been closed by Mousemonkey