Is it just me?

[racolvin]

And no I don't mean the ability to twist it/bend it 🙂

I'm just talking about how the PCI-e slots are done. What's with the whole "1 16x slot and 1 1x slot" business? Is it just me or does that seem really limiting somehow? What if I had another PCI-e card I wanted to use that was 8x?

So far, I don't find a non-server mobo that can do a 16x slot for video and a 8x slot for a dedicated RAID controller - am I looking in the wrong places? Does anyone know of a good mobo that has that sort of slot configuration?

R

 

[Green Man]

The problem is with the chipsets. nforce4 and i915 / i925 have 20 PCI-E lanes. after video, you don't have 8 more lanes.

 

[racolvin]

Ahh, now see that explains a lot. I had no idea there was a limitation like that - would you or anyone else happen to have a link to a good explanation of how that works, etc?

 

[Concillian]

PCI-e is integrated into the chipset.

PCI-e works on number of available lanes. x1 takes 1 lane, x4 takes 4, etc...

nForce4 only has 20 lanes available.
Some server boards have chipsets with more lanes available.
As PCI-e catches on, you can expect more lanes on a typical board. Future chipsets will certainly have more than 20 lanes.

You don't necessarily need all the bandwidth of x16 for video, so you do have the option of an SLI board. That will generally split the two x16 slots into two x8 slots. This allows usage of an x16 video card (at a reduced throughput of x8 speeds), and usage of the other x16 slot for any PCI-e card, and will give up to x8 throughput.

Any PCI-e card physically smaller than the slot can be used in any PCI-e slot...
A PCI-e x1 card can fit and work in an x1, x2, x4, x8, or x16 slot
x2 cards work in x2, x4, x8, and x16 slots
x4 cards work in x4, x8, and x16 slots
etc....

 

[Appledrop]

lol i came into this thread expecting replies regarding how many layers in the pcb 🙁