What happens when you mix different GTX 670s for SLI?

[poohbear]

Hey all, i'm buying a 2nd GTX 670 but its a Gigabyte GTX 670 WF2 (it has 2 fans) and it has a lower factory boost overclock than my Gigabyte GTX 670 WF3 (3 fans). The WF2 has a 1019mhz boost, and my WF3 has a 1075mhz. From what i read they have different PCBs (WF2 is quieter and shorter, WF3 has better voltage regulators) but both are obviously GTX 670s. Will they play nice together? Will the only difference be that they boost to the slower GTX 670? (ie 1019mhz)

Thanks in advance for any clarification!

 

[bystander36]

Ultimately, it is best to have the same cards, but with the frame metering technology that SLI uses, it shouldn't be a problem. I personally am in the same boat, and it runs quite nicely.

 

[poohbear]

well "shouldn't be a problem" is a bit risky for dropping another $260 on a 2nd used card. i want it to work as smooth as possible. I'd rather buy a new Gigabyte WF3 and pay the extra $100 if it means it'll work flawlessly.

What kind of problems can i expect from mixing 2 cards aside from running @ the lower clocked one?

 

[felang]

well "shouldn't be a problem" is a bit risky for dropping another $260 on a 2nd used card. i want it to work as smooth as possible. I'd rather buy a new Gigabyte WF3 and pay the extra $100 if it means it'll work flawlessly.

What kind of problems can i expect from mixing 2 cards aside from running @ the lower clocked one?

No problem whatsoever. If for some reason you want to match both cards clocks, you can use MSI Afterburner or EVGA Precision X to slightly overclock the "slower" card to match GPU clocks.

 

[Termie]

It won't be a problem, actually, but you should probably use MSI Afterburner to individually set the clocks on each one so that they'll run at the same boost. That's going to be partly dependent on temps, and one may run hotter than the other, but that's true even of identical cards, as one may get less fresh air. So just experiment a bit.

And even if they're running at different clocks, it's still fine - one just won't be running at the same level of GPU Usage.

 

[bystander36]

well "shouldn't be a problem" is a bit risky for dropping another $260 on a 2nd used card. i want it to work as smooth as possible. I'd rather buy a new Gigabyte WF3 and pay the extra $100 if it means it'll work flawlessly.

What kind of problems can i expect from mixing 2 cards aside from running @ the lower clocked one?

Like I said, I use two different 680's in SLI and I haven't seen a problem. The fact that boost causes both cards to constantly end up at different clock rates anyways, the frame metering is the feature that keeps the times between frames constant, even with the same cards.

I use EVGA Precision X to have their base clocks the same, but due to boost affecting each card differently, they usually are at different clocks regardless.

 

[poohbear]

ok thanks, do i just put the 2nd card in and use the SLI bridge and that's it they're good to go?

 

[bystander36]

ok thanks, do i just put the 2nd card in and use the SLI bridge and that's it they're good to go?

You have to enable them in the Nvidia Control Panel after you log in as well, and any time you update the drivers.

 

[poohbear]

ok thanks alot for explaining everything guys! much appreciated and on to SLI!^^

 

[Evilviking]

ok thanks, do i just put the 2nd card in and use the SLI bridge and that's it they're good to go?

I need to plug a 4 pin molex power (fan plug) into my mobo in order to use sli or xfire (power and stabilize 2nd pci express slot). Check your board.

 

[bystander36]

I need to plug a 4 pin molex power (fan plug) into my mobo in order to use sli or xfire (power and stabilize 2nd pci express slot). Check your board.

Umm...I believe you have the wrong card in mind. The 670 should have two 6-pin PCIe power connectors.

 

[Evilviking]

Umm...I believe you have the wrong card in mind. The 670 should have two 6-pin PCIe power connectors.

It's a molex power connection located on the mobo itself. High end asrock and asus rog mobos (probably others) require an additional power connection on the mobo as well as the 2 power connections per card.

 

[poohbear]

Ive already connected all possible connectors to the mobo, no more room to connect anything really.