How many PCI-e lanes supported on SB-E?

[wonderbread57]

I've heard it was 40 lanes supported but I'm reading VR's preview of the upcoming Sapphire X79 board and it mentions that 3 of the 6 slots are x16 capable and all 6 are x8 capable. So that means it can run 3 cards at x16 (48 lanes)?

Help me out with this please.

 

[dma0991]

According to AT it is either 2x16 or 4x8 only but it might have changed. AFAIK most boards that supports more than 3 slots of PCIE x16 would rely on a 3rd party chipset like the Nvidia NF200.

 

[AdamK47]

According to AT it is either 2x16 or 4x8 only but it might have changed. AFAIK most boards that supports more than 3 slots of PCIE x16 would rely on a 3rd party chipset like the Nvidia NF200.

It's 40 total lanes and there are 4x SLI X79 boards coming out without the NF200. The Gigabyte GA-X79-UD7 and the EVGA X79 Classified are a couple of examples.

 

[wonderbread57]

So where does the 40 limit exist, the CPU? And if so, was this always the intended spec or is it low because of some PCI-e/Intel screw up? Also, will future LGA2011 CPUs somehow be able to utilize more than 40 lanes from the same motherboards we are seeing now?

 

[Edrick]

So where does the 40 limit exist, the CPU? And if so, was this always the intended spec or is it low because of some PCI-e/Intel screw up? Also, will future LGA2011 CPUs somehow be able to utilize more than 40 lanes from the same motherboards we are seeing now?

I believe it is 40 lanes inside the CPU at PCIe 3.0 speeds (although not certified PCIe 3.0). Then an additional 8 lanes of PCIe 2.0 on the x79 chipset.

At least that is what I heard. We will know for sure in a week or so.

 

[greenhawk]

So where does the 40 limit exist, the CPU? ... will future LGA2011 CPUs somehow be able to utilize more

it is part of the CPU spec (ie: number of pins given the task of transfering this information.

As to future ones, no. All the pins in the socket I suspect are in use, so only way to add more would be a more pins so a new socket and a new motherboard.

edit: considering how many SB had, the number will not be a issue for a lot of people.

 

[IntelUser2000]

I believe it is 40 lanes inside the CPU at PCIe 3.0 speeds (although not certified PCIe 3.0). Then an additional 8 lanes of PCIe 2.0 on the x79 chipset.

At least that is what I heard. We will know for sure in a week or so.

Yep, that sounds right.

 

[gorydetails]

wow,, 40 pins, that's it?

 

[AdamK47]

40 PCI-E 3.0 lanes on die and 8 PCI-E 2.0 DMI lanes. X58 has 36 PCI-E 2.0 lanes on the chipset and 4 PCI-E 2.0 DMI lanes.