Do Z77 boards with Sandy Bridge have crippled PCIe bandwidth?

[BVKnight]

Problem 1: Some Z68 boards didn't have enough PCIe bandwidth to run all PCIe slots at their full speed and/or power all their ports, when one of the last PCIe slots on the board was occupied. See here: http://www.tomshardware.com/reviews/asrock-z68-extreme4-asus-p8z68-v-pro-gigabyte-z68x-ud3h-b3,2939-5.html

Lacking the PLX bridge found on the company's more expensive products, it’s impossible to populate all of the P8Z68-V Pro’s interfaces simultaneously. The second PCIe x1 slot is, for example, shared with the front-panel USB 3.0 controller and the four-lane x16-length bottom slot. When one of the two slots is filled, electronic switches disable the other two interfaces. The features get even sparser when the bottom slot's x4-mode is enabled; doing so disables the first x1 slot and the eSATA controller.

Problem 2: The Sandy Bridge and Ivy Bridge chips have PCIe lanes built into the chip itself. I can't find whether IB has more of these lanes than SB.

Question: If I buy a Z77 board that doesn't have a PLX chip, but plug in a Sandy Bridge processor, will it be able to power all the PCIe slots at full speed and power all the ports, simultaneously?

 

[aicom]

Answer 2: Ivy Bridge has the same number of PCIe lanes as Sandy Bridge.

Answer: It depends on the board. If the manufacturer has overused the PCIe lanes such that switching is necessary, then no, not even with IB could you use all of them at once.

EDIT: Adding more PCIe lanes would need more traces to the CPU and require a new CPU socket.

 

[BVKnight]

Answer 2: Ivy Bridge has the same number of PCIe lanes as Sandy Bridge.

Answer: It depends on the board. If the manufacturer has overused the PCIe lanes such that switching is necessary, then no, not even with IB could you use all of them at once.

EDIT: Adding more PCIe lanes would need more traces to the CPU and require a new CPU socket.

Perfect, thanks. That's just what I needed to know.

 

[BVKnight]

Best answer selected by BVKnight.

 

[Maziar]

This topic has been closed by Maziar