Wiring Crossfire with 2 PSU's...?

[Darren]

Now I know right off the bat this isn't the greatest idea in the world but if it's doable I want to try it. Basically a friend of mine has a near identical machine to mine (poser) and we wanted to Crossfire our 390's for ships and gigs.

Is it possible to wire up the 2 390's with the 2 CX600's we have? I know you can do the paperclip trick to get a PSU to turn on separately, but I don't want to be frying our cards, power supplies, or ourselves. Is it feasible to do it this way? If so, any specific way to wire it up to prevent any damage and make it work properly?

This is nothing permanent, just something we want to to try to see if it works. And yeah, we'll be dealing with low bandwidth slots. Meh.

Feel free to tell me I'm an idiot for trying, but if it's feasible I'll give it a shot.

 

[AdmnPower]

I assume you're running the cards in the same machine and are just planning on jerry rigging the power supplies in order to have enough power for both cards without having to go out and buy a bigger power supply just to do the test. Am I correct?

If that is indeed the case, you should be fine with the paper clip trick, the main power supply would have more load because you'd have to power the CPU and other components off of one of them. Offloading the power consumption of the second card to a second power supply would be fine though. The card doesn't have any way to notice or care that it's power isn't coming from the same place as the other card.

I have a friend who took a number of computer power supplies and soldered their 12v rails together in order to run a car amplifier that powering two 12inch subs that were connected to his living room sound system. Had to add a 1 farad capacitor because they pulled too much when the volume was turned up and also had to jump start the capacitor with a car battery if the system ever got unplugged or turned off but other than all of that it worked great. Moral of the story, computer power supplies are versatile.

 

[spirit]

Yeah you can get those adapters that take two 24-pin power connectors and adapt them into one. Plug that into the motherboard and then simply connect the other 390 to the appropriate connectors on one of the power supplies and it should be fine.

If it's not permanent then the paper clip trick will work too and save you a few bucks. Obviously you only need to do that on one of the power supplies because the 24-pin power cable on the PSU will need to go into the motherboard.

I would probably advise having one 390 powered off one of the PSUs and the other powered off the other - I wouldn't 'mix and match'.

If you think about it logically, all the other CX600 will be doing is powering a graphics card and your existing CX600 can already power a graphics card and the other components in your system, so you will be absolutely fine. I don't see why it wouldn't work.

 

[AdmnPower]

Yeah you can get those adapters that take two 24-pin power connectors and adapt them into one. Plug that into the motherboard and then simply connect the other 390 to the appropriate connectors on one of the power supplies and it should be fine.

That's awesome, I didn't know they made such a cable!

 

[spirit]

That's awesome, I didn't know they made such a cable!

Yup!

 

[beers]

Yup!

For some reason I was expecting something other than a fancier looking paperclip mod

 

[AdmnPower]

I'm a little dissapointed as well. To be honest though, I don't actually know what I was expecting.

 

[Okedokey]

Yeah that adaptor will work find. Just balance the PCIe loads across both PSUs.

 

[spirit]

I'm a little dissapointed as well. To be honest though, I don't actually know what I was expecting.

So sorry to disappoint!