[geeks] pci express x8 video card?

[Charles Shannon Hendrix]

Tue, 13 Feb 2007 @ 22:13 -0600, Doug McLaren said:

> On Tue, Feb 13, 2007 at 11:03:46PM -0500, Sridhar Ayengar wrote:
> 
> | Francois Dion wrote:
> | > Looking for an nvidia video card that is pci express x8, if there is
> | > such a thing? All I see is x1 or x16. Anything x4 or x8?
> | 
> | Not that I've ever heard of.  Only x1 and x16.  Why not just use an x1 
> | card in that x8 slot?
> 
> I believe the really cheap ECS board that has a GeForce 6150 built in
> also has an x16 slot that runs at x8.  I assume that it can use
> standard x16 PCI-E video cards, but I'm not certain of that.
> 
> And I think the x1 PCE-E slots are totally different, and there's not
> much out there that can use them yet.

PCIe is technically all one bus with N lanes.  The lanes are divided up
into slots.

For example, my motherboard has an nforce4 chipset with 20 lane PCIe. It
is divided into 4 slots: 16x, 1x, 1x, 4x. If you use a 4x card in the
4x slot, the other two are disabled (I think, it might try to share, I
don't know).

If you put a video card in the 4x slot (it has one open end, and
circuitry to detect video), then it will allow SLI mode to work at
reduced bandwith.

Outside of special handling like that, the only difference between one
slot and another should be the number of lanes.


-- 
shannon / Asus A8N5X - Opteron 170 at 2.5GHz  | But you know, a little Sun Ultra 1
-------'  2GB RAM - nVidia 7900GS          | is doing all the hard work...