Why can you only have 4 gpu's maximum in a crossfire / Sli setup?

[MekaMain]

Hi guys

 

I was wondering why you only is able to have 4 gpu's in a crossfire / Sli setup at maximum. Because it would be pretty awesome to have like 4 7990 or 690 in a  crossfire / sli setup  ;)

 

Thanks 

[MegaDave91]

There's only so many PCIE slots on a motherboard.

[joelthezombie15]

@MegaDave91 its not a motherboard problem

 

 

its a driver and card problem.

[d33g33]

I don't exactly know but it would be more complicated than I have the slots so why not. 690 and 7990 are already in SLI/Crossfire essentially. I would say its and physical architecture limitation, not just a driver restriction.

[Bluejay0]

Hi guys

 

I was wondering why you only is able to have 4 gpu's in a crossfire / Sli setup at maximum. Because it would be pretty awesome to have like 4 7990 or 690 in a  crossfire / sli setup  ;)

 

Thanks 

Today's motherboards can only support so many PCIE slots, most companies dont have more than 8 from what i've seen. The power compsumtion would be ENOURMOUS (above 1300 watts min.) and the scalable link interface can only support a maximum of 4 cards in the link. NVIDIA and AMD's SLI and Crossfire X drivers either way have problems with multiple cards running together.

[KittenHat]

Also isn't there just so much bandwidth for pci lanes

[Bleedman0xx]

Not just the number of physical PCIe slots or driver/card limitations but also the number of PCI lanes the CPU allows is also a limiting factor.

 

An current Intel consumer-grade cpu is limited to only 16 PCI lanes where as the Intel enthusiast-grade CPU allows 40 PCI lanes. And that's still stretching it for a 4-way SLI/Crossfire setup.

[delet my acc pls]

and no games would support it either and it would scale incredibly bad

[MegaDave91]

Practically speaking, who would want to SLI more than 4 cards anyway?

[Bluejay0]

Practically speaking, who would want to SLI more than 4 cards anyway?

Rich people

[sabot]

There are some bit coin mining machines with lots of gpus and other systems that use the gpus for work. They are enterprise boards designed for advanced modeling etc.

[Bluejay0]

There are some bit coin mining machines with lots of gpus and other systems that use the gpus for work. They are enterprise boards designed for advanced modeling etc.

You mean the Workstation boards