Sandybridge and PCIe lanes

[SciFi]

Hi guys,

I am slowly starting the process of planning my first major PC build for a few years and whilst researching I came across something odd and wanted to see what peoples thoughts were.

I have been running a Q6600 for about 4 years now (it just keeps giving ;-) ) and when I selected the MB for it way back when I was very careful to go with a board that had SLI support with full 16 lanes on each PCIe16 slot.

When looking at the new SandyBridge boards it seems to be that they all only support 1 PCIe16 with 16 lanes and the other one or two (!!) at 8 lanes each.

This is really odd as the older Core i7 boards also seem to support the 2 * 16 lane setup.

It is my intention to build a nice SLi system that will last me into my 40's so can you tell me should I care about this? Should I go for the older boards and non SB CPU's ?


Thanks in advance :-)

-SciFi

[kalniel]

Older 1156 (lynnfield core i3/5/7) boards only support 2x8, so it's not a huge surprise that their replacement, the 1155 boards, also only support 2x8 (or 1x16). To get 2x16 (and more) you need to go for an x58 motherboard (stk 1366).

As for whether 2x8 is limiting, it's very unlikely, as they are gen 2 of the PCI-E lanes, twice as fast as gen 1.

Alternatively you can/will be able to find sandy bridge boards that use NF200 bridging chips to allow high bandwidth card to card communications, effectively boosting the number of lanes for SLI/Crossfire.

[SciFi]

Older 1156 (lynnfield core i3/5/7) boards only support 2x8, so it's not a huge surprise that their replacement, the 1155 boards, also only support 2x8 (or 1x16). To get 2x16 (and more) you need to go for an x58 motherboard (stk 1366).

As for whether 2x8 is limiting, it's very unlikely, as they are gen 2 of the PCI-E lanes, twice as fast as gen 1.

Alternatively you can/will be able to find sandy bridge boards that use NF200 bridging chips to allow high bandwidth card to card communications, effectively boosting the number of lanes for SLI/Crossfire.

Thanks for that. It was the x58 boards that I was looking at but I did not know that they had iterated PCIe!

I guess I am trying to choose between Ci7 + X58 or the newer SB CPU's and chipsets.



Also, as I am here... anyone know of a desktop or cube style case that would fit a pair of Nvidia 470's and, probably more difficult, a Coolermaster V10 cooler (already have, and it's very good!).

Thanks

-SciFi

[kalniel]

Thanks for that. It was the x58 boards that I was looking at but I did not know that they had iterated PCIe!

I guess I am trying to choose between Ci7 + X58 or the newer SB CPU's and chipsets.

For gaming, the SBs have it - games still need high clock speeds first and foremost, and SB delivers that in spades. You won't run out of lanes just for graphics with SB (especially if you go for a NF200 solution). However it's other peripherals that might be limited - I was looking at SSDs and they start gobbling PCI-E lanes as well, especially when the PCI-E card ones look so tasty. But they aren't needed for games, so unless you think you will be going down that route SB would be highly recommended (though personally I would wait for the chipset revisions with a fixed sata controller).

[SciFi]

Thanks again.

My planned setup is something like a pair of smaller SSD's Raid0 for boot drive then a pair of HDD's in Raid0 for data, The pair of 470's and as much RAM of the fastest type I can afford.

Only need to choose the CPU and MB now :-)

-SciFi