Oh men problems! [Ibex-Peak and Lynnfield - 32 PCI-Express lanes but just 16 active!]

[HamidFULL]

Hello Men!

These days I'm researching on Ibex-Peak (specially P55) + Lynnfield platform and I got some of big problems!!

As we know :
(i). Each Lynnfield CPU has 16 PCI-Express lanes
(ii). Each Ibex-Peak (P55 PCH) has 16 PCI-Express lanes
(iii). Lynnfield is connected to Ibex-Peak (P55 PCH) with DMI [thats slow for GPUs]

Now questions :
1. When a P55 motherboard has 2 PCI-Express slots they should be provided by Lynnfield CPU not P55 PCH because DMI is slow, right?

2. if "1" is true then why Ibex-Peak (P55 PCH) has 16 PCI-Express lanes?! actually they are dead with DMI!!

3. I found that some of P55 solutions (like Jetway HI05) has three PCI-Express slots, anyone knows about the configuration?!



Thanks in advance ...

[zanzabar]

i think that that jetway has a special slot for some proprietary card.

for the p55 it looks like the best option is to get something with 8x8 or 8x8x4 (with the 4 from the p55 and the 8x8 from the cpu), if u get a slot controller like the nf200,plx or hydra u are just adding in latency and with the plx and hydra some direct gpu to gpu bandwidth and that would be worthless IMO since the cards of now with 1 gpu per slot work great on 8x with almost no hit.

u have to remember that the p55 is a midrage platform intel wants to force people who want 3/4 gpus to the i7

[Hornet331]

Migis picture from expreview should make thing clear, although it shows clarkdeal and not Lynnfield:

Lynnfield has 16 lanes that are available for the GFx and can be 16x or split to 8x8. The P55 has 8 lanes available, but most of them will be occupied by 3rd party controllers (sata3.0, usb3.0, GbE, etc.) so i guess you will have approx 4 left to be assigend.

Boards with 3 16x slots usually will only have it phsically and the 3rd slot will be 4x electrical as zanzabar already explained.

[Migi06]

Migis picture from expreview should make thing clear, although it shows clarkdeal and not Lynnfield:

Lynnfield has 16 lanes that are available for the GFx and can be 16x or split to 8x8. The P55 has 8 lanes available, but most of them will be occupied by 3rd party controllers (sata3.0, usb3.0, GbE, etc.) so i guess you will have approx 4 left to be assigend.

Boards with 3 16x slots usually will only have it phsically and the 3rd slot will be 4x electrical as zanzabar already explained.

http://en.expreview.com/2009/08/19/t...-i5-750.html/4

[HamidFULL]

zanzabar - Hornet331 - Migi06 --> thanks! I got my answer