PSU needed to crossfire 5770's?

[davedarave99]

Hi i recently asked on these forums about which graphics card to upgrade to from a hd 4850. I have decided to buy a pair of 5770's and i was wandering how watts i would need.

I currently have a antec earthwatts 500w power supply. I have read from the ati website that you need a 600w PSU minimum to run 2 in crossfire.

My question is will my 500w do the job??

Also i have 2 x 6pin PCI express connectors, is that all i need to run 2 5770's thanks in advance =)

 

[stulid]

I wouldn't be surprised if your 500w psu is upto the job.

Its from a very good psu manufacturer.

The 5770 is low power consumption, and you already got the two pci cables needed.

 

[Meaker]

Yeah thats fine, a top notch 400W could do it.

 

[cuda-uk]

Yeah thats fine, a top notch 400W could do it.

Surely it will depend on what else is running in the system i.e cpu, number of hard drives, amount of ram, fans etc.
I have just toasted a 700w psu running 2x 4890's and had to upgrade/replace it. Try and find a psu that uses a single rail as they apperantly are more stable when running duel graphics.

 

[e36Adz]

I have just toasted a 700w psu running 2x 4890's and had to upgrade/replace it.

Which PSU were you using ???

 

[IIGAZI360II]

Most importantly you want to look out for how many amps each card is going to need, and how many the +12V rail(s) on the power supply supplies

 

[eddie86]

Try the Antec power supply calculator on their website.

 

[RJC]

Looking through the op last thread his got a Overclocked 955.

The PSU should be enough, my i7 setup with xfire 5850 pulls 480w from the mains.

 

[sunderland]

well ive got a 520hx corsair and i could not get my 2 cards to run without the odd reboot and shutdown,both cards are fine on there own but together no matter what drivers i use it does it,this is of guru,was thinking of getting another psu to try,my hx520 only has 50 amps on the 12v rails so it could be that


Radeon HD 5770 CrossfireX (2-way)
A second card requires you to add another 108 Watts. You need a 550 Watt power supply unit if you use it in a high-end system. That power supply needs to have (in total accumulated) at least 55 Amps available on the +12 volt rails.

 

[Technics]

a 450/500 watts plus should about do the job unless you have loads of case fans and a large overclock on your rig already

 

[C64]

well ive got a 520hx corsair and i could not get my 2 cards to run without the odd reboot and shutdown,both cards are fine on there own but together no matter what drivers i use it does it,this is of guru,was thinking of getting another psu to try,my hx520 only has 50 amps on the 12v rails so it could be that


Radeon HD 5770 CrossfireX (2-way)
A second card requires you to add another 108 Watts. You need a 550 Watt power supply unit if you use it in a high-end system. That power supply needs to have (in total accumulated) at least 55 Amps available on the +12 volt rails.

Corsair hx520 is 40A 12v rail the corsair hx620 is 50A

btw did you try using the pci-e power connectors both plugged in to separate points none ran off of molex or anything like that ? I mean both separate each lead going from card directly to the power supply.

The corsair hx 520 should be running 2x5770 easy so sounds like something else is up there.

 

[Meaker]

Surely it will depend on what else is running in the system i.e cpu, number of hard drives, amount of ram, fans etc.
I have just toasted a 700w psu running 2x 4890's and had to upgrade/replace it. Try and find a psu that uses a single rail as they apperantly are more stable when running duel graphics.

Well considering 2x HD 5770 use a bit more power than a single 4890 helps.

Also it sounds like a faulty PSU as 2x HD 4870 and an OCed i7 maxes out a 500W PSU (I have checked). However that is only when running a CPU stress test and heavy 3d game at the same time.

 

[sunderland]

Corsair hx520 is 40A 12v rail the corsair hx620 is 50A

btw did you try using the pci-e power connectors both plugged in to separate points none ran off of molex or anything like that ? I mean both separate each lead going from card directly to the power supply.

The corsair hx 520 should be running 2x5770 easy so sounds like something else is up there.

C64 none were ran of molex and i only have 1 hardrive and 4 120fans,dvdwriter,i checked Antec power supply calculator and it says i need at least 625w for my system so i dont no if i should get a new psu and find out its not that,but what else could it be,both cards run fine on there own

also if mine only has 40amps and guru say you need at least 55amps are they not right,i dont no

 

[RavenXXX2]

You're cutting it fine with a 520 watt PSU, upgrade it to a 700 watt and future proof yourself in the process.

 

[Meaker]

You're cutting it fine with a 520 watt PSU, upgrade it to a 700 watt and future proof yourself in the process.

I would say its optimal for the rating of the PSU.

 

[paradigm]

I run the following off an Antec HE 550W:

Intel DX38BT
Q6600 @ 3.7GHz
8GB PC3-10666 DDR3
6x 7200 RPM HDD's
2x 32GB eSATA SSD drives
2x Radeon 5770's
1x GeForce 9800GT
3x 120mm fans
2x 140mm fans
2x DVD-RW's

 

[sunderland]

I run the following off an Antec HE 550W:

Intel DX38BT
Q6600 @ 3.7GHz
8GB PC3-10666 DDR3
6x 7200 RPM HDD's
2x 32GB eSATA SSD drives
2x Radeon 5770's
1x GeForce 9800GT
3x 120mm fans
2x 140mm fans
2x DVD-RW's

and how many amps is on your 12v rails if you dont mind me asking paradigm

 

[C64]

(54 A) that PSU is but just look what's on there am sure there's people running 2x5770's fine on the corsair hx520 tbh.
Will see if I can find someone.

 

[Devrij]

5770 draws 110W under load iirc so you should be fine unless your case is full of cathodes/fans and is running a high OC

 

[krooton]

My entire pc with a single 5770 draws 220W at gaming load, crossfiring 5770s would totally be possible with a decent 500w with plenty of headroom to spare.