Support for Crossfire but not SLI?

[StephenP85]

It seems that there are quite a few motherboards out there that support Crossfire but not SLI. The Biostar Hi-Fi Z87X 3D, for example, which was reviewed here recently, only seems to support Crossfire.

Can someone explain why this is the case? What else is needed to make it also SLI ready?

 

[Dark Lord of Tech]

http://www.tomshardware.com/forum/245454-33-crossfire-faqs

 

[Sakkura]

Nvidia requires that each card in a SLI configuration has at least an x8 connection. Crossfire only requires x4. Motherboard makers can save some money by going for an x16 / x4 configuration, which will support Crossfire but not SLI. More expensive motherboards go x8 / x8 which allows for SLI and also provides better Crossfire performance.

 

[StephenP85]

Thank you for the link. Unless I've completely missed something, that page tells me that SLI won't work in a motherboard that only supports crossfire, but it doesn't tell me why. Is there an explanation buried in some of the links posted? Some of those links were broken, unfortunately.

 

[StephenP85]

Nvidia requires that each card in a SLI configuration has at least an x8 connection. Crossfire only requires x4. Motherboard makers can save some money by going for an x16 / x4 configuration, which will support Crossfire but not SLI. More expensive motherboards go x8 / x8 which allows for SLI and also provides better Crossfire performance.

This is what I thought as well, but the Biostar Hi-Fi Z87X 3D seems to be a typical haswell board with two PCIe 3.0 x16 slots, and it for some reason supports crossfire x8/x8 but not SLI.

 

[Sakkura]

Well it's Biostar. They do weird things.

 

[ghostofChrist]

Nvidia requires that each card in a SLI configuration has at least an x8 connection. Crossfire only requires x4. Motherboard makers can save some money by going for an x16 / x4 configuration, which will support Crossfire but not SLI. More expensive motherboards go x8 / x8 which allows for SLI and also provides better Crossfire performance.

My motherboard supports xfire but not sli it has a pcie 3.0 x16 and a 2.0 x16, is the reason it doesnt support sli because one is 2.0 and the other 3.0? the motherboard in question is the msi z87-g43 gaming.

 

[Sakkura]

Nvidia requires that each card in a SLI configuration has at least an x8 connection. Crossfire only requires x4. Motherboard makers can save some money by going for an x16 / x4 configuration, which will support Crossfire but not SLI. More expensive motherboards go x8 / x8 which allows for SLI and also provides better Crossfire performance.

My motherboard supports xfire but not sli it has a pcie 3.0 x16 and a 2.0 x16, is the reason it doesnt support sli because one is 2.0 and the other 3.0? the motherboard in question is the msi z87-g43 gaming.

No, it's because the second slot is PCIe 2.0 x4.