Aces High Bulletin Board

General Forums => Hardware and Software => Topic started by: Krusty on September 26, 2006, 12:45:55 PM

Title: Running PCIe x16 on a x4 port?
Post by: Krusty on September 26, 2006, 12:45:55 PM

A couple of motherboards with dual AGP/PCIe say they have the PCIe port really rated at 4x. If you stick a GeForce 7000 series in there is it going to severely down-rate the card? How much of the "x16" is truly used? I know the upper limits are nowhere near being reached yet. Heck even AGP hasn't maxed out yet. However, before I go that way I want to be sure it'll be a good move, and not one that will lead to crippling fps and the like because the port is sub-par.

Title: Running PCIe x16 on a x4 port?
Post by: Krusty on September 26, 2006, 01:29:13 PM

Heh, answered my own question:

anandtech forums were talking about this, and in relation to the mobo I was thinking of, the fps hit when running a PCIE GeForce 7900 is only about 11% (and that's one of the TOP end cards) as compared to a full x16 PCIe slot.

Title: Running PCIe x16 on a x4 port?
Post by: Sancho on September 26, 2006, 02:59:39 PM

you saw this (http://www.anandtech.com/mb/showdoc.aspx?i=2814&p=3), right?  basically, identical video chipsets will be slightly slower on PCI-E 4x ports than AGP 8x ports.  But not massively slower.

Title: Running PCIe x16 on a x4 port?
Post by: Krusty on September 26, 2006, 04:58:27 PM

Ah, no I hadn't. I did a google search and found a thread in the forums with about 8 pages on this mobo. One had a link to one article somewhere on anandtech and said about 11% but, reading the AGP/PCIe comparison I don't know really.