550vx enough for 4850 crossfire?

[krllz]

Hey I've got a corsair 550vx and wondering if it could run two 4850s in crossfire? I think it has 42a on the 12v rails.

I'd say at stock it could but I currently have 3 sata II hard drives, a fan controller, two DvD drives an overclocked 955@1.53v under load 4 1gb ddr3 ram sticks@1.5v and my current single 4850 bios modded with the max stock voltage and ALOT of fans like 12 in total. Can anyone tell me if it's enough?

 

[rolli59]

Based on all your drives, fans and etc; It might be pushing it.

 

[jyjjy]

Yeah ordinarily I would say yes but considering the rest of the system...

 

[builderbobftw]

Nope. Stick to you're current 4850, or if you don't have one, buy a 5850/5770 instead.

 

[krllz]

I didn't think it would work very well myself honestly, and if it did it'd be maxed out most of the time, although being a corsair would it not have a little more headroom that rated for? that and it's got a 5 year warranty, what'yah guys think?

Unfortunately I only have around 90 euros spending money right about now, that could get me at best another 4850, or I could possibly get a bigger PSU for later on and save up for something like a 5850 or one of the new Nvidia cards, also about the 5770, could I run two of those in xfire with the 550? They run a fair amount less power than the 4800 series right?

 

[shubham1401]

Well you should be able to run it.

Why don't you run the 955 at stock speed for a while and use those 2 cards.

 

[jsc]

I'd say at stock it could but I currently have 3 sata II hard drives, a fan controller, two DvD drives an overclocked 955@1.53v under load 4 1gb ddr3 ram sticks@1.5v and my current single 4850 bios modded with the max stock voltage and ALOT of fans like 12 in total. Can anyone tell me if it's enough?

Let's see.
OC'd CPU - 10 amps @12 volts = 120 watts
4 GB RAM - 6 amps @ 3.3 volts = 20 watts
2 OC'd 4850's -18 amps @12 volts = about 210 watts
3 Hd's & 2 opticals - 4 amps @ 5 volts & 6 amps @12 volts = 90 watts
Motherboard - 4 amps @ 5 volts & 1 amp @ 12 volts = 30 watts
12 fans (why?) - 3 amps @ 12 volts = 36 watts.

That's about 410 watts and 37 amps @ 12 volts. You're operating your PSU at a higher load factor than I would, but the Corsair will work.

 

[shubham1401]

^But If he runs those cards at stock clocks it will use lesser power.

Also a 955 on stock speed is powerful enough to handle 4850 CF(Well does it makes a difference if you have 90 fps instead of 1650fps?)

 

[krllz]

Well you should be able to run it.

Why don't you run the 955 at stock speed for a while and use those 2 cards.

I'd be really sore about doing that :lol:

Let's see.
OC'd CPU - 10 amps @12 volts = 120 watts
4 GB RAM - 6 amps @ 3.3 volts = 20 watts
2 OC'd 4850's -18 amps @12 volts = about 210 watts
3 Hd's & 2 opticals - 4 amps @ 5 volts & 6 amps @12 volts = 90 watts
Motherboard - 4 amps @ 5 volts & 1 amp @ 12 volts = 30 watts
12 fans (why?) - 3 amps @ 12 volts = 36 watts.


That's about 410 watts and 37 amps @ 12 volts. You're operating your PSU at a higher load factor than I would, but the Corsair will work.

Cheers for the roundup man, I'm not good with calculating all that stuff, I'm guessing the 80% efficiency makes that pretty much topped out? Will good air cooling help the PSU under the load? Or would it die just as fast? I think I'm gonna go for it, even if it causes trouble down the road at least I can say I've crossfired one time or another

 

[krllz]

@shubham1401 Nope, it wouldn't. But I'd feel guilty having something at stock when I've already tested it for hours on end and know it's stable as a rock *shudders*

 

[megamanx00]

80 Percent efficiency just means that 80% of what is being drawn from the wall is being supplied to your system. The Corsair can supply 550W to your system, in which case it would be drawing about 690W from the wall. Anyway.......

Yeah that PSU should be enough, though you will be stressing it.