GPU's on separate PSU

[Dirk Diggler]

Could I run 4 way SLI with two cards on the system PSU and the other two on a separate PSU?

I want to run quad 780's and I have a 1200w & 1000w PSU's. 1200w I would allocate to the system and 2*GPU and 1000w I would allocate only to the other two GPU's.

Would there be any issues with polarity?

 

[Flippy]

You can do this without any issues. Lian Li make an adapter so you can connect both power supplies and have them turn on at the same time
http://www.legitreviews.com/add2psu-daisy-chain-power-supply-adapter-review_1698

 

[spoffle]

It's really easily to do this, however I don't think it'd be worth the hassle.

 

[Dirk Diggler]

It's really easily to do this, however I don't think it'd be worth the hassle.

If I didn't do this I'd need to buy a 1600w PSU, maybe even 2Kw so it's definitely worth it for me.

Thanks for the confirmation and also the link to that adaptor.

 

[spoffle]

I mean the quad 780s isn't worth the hassle.

 

[Dirk Diggler]

I mean the quad 780s isn't worth the hassle.

I'm benching them mate, they're not for gaming (I've got a 1080ti for that).

 

[Kaapstad]

You can do this without any issues. Lian Li make an adapter so you can connect both power supplies and have them turn on at the same time
http://www.legitreviews.com/add2psu-daisy-chain-power-supply-adapter-review_1698

You don't even need any fancy connectors if you use two or more PSUs.

Just use the white connector on the second PSU 24 pin lead (like you get in watercooling kits for testing) to fool it into thinking it is plugged into the motherboard.

https://www.overclockers.co.uk/xspc-psu-bridging-connector-24-pin-wc-021-ok.html

 

[Dirk Diggler]

@Kaapstad I've got one of those already. I'm assuming it wouldn't do the GPU any harm if it received power in that way before the main system (and therefore the PCI) was switched on?

 

[andybird123]

@Kaapstad I've got one of those already. I'm assuming it wouldn't do the GPU any harm if it received power in that way before the main system (and therefore the PCI) was switched on?

Not at all, i ran a 3 gpu system with 3rd on 2nd psu this way for 2 years without problems, you can boot the pc and then power 2nd or power 2nd first then boot, either works and is fine

 

[Sasahara]

Not at all, i ran a 3 gpu system with 3rd on 2nd psu this way for 2 years without problems, you can boot the pc and then power 2nd or power 2nd first then boot, either works and is fine

You should check the following when doing this.

Your 2nd or 3rd PSU should be a "DC to DC circuit" design PSU as they can run on very low loads or none at all.
Using the older tech, "Magnetic Amplifier Circuit" design PSUs may cause problems as they tend to require a minimum load on the 12V, 5V and 3.3V to run correctly. If you have one of these, use it as the initial PSU connected to the Mobo and other random low powered components.

Generally Magnetic Amplifier Circuit PSUs will be the cheaper budget models Silver/bronze or lower rated models. Most if not all gold or better rated PSUs will be DC to DC circuit design.