@eagl
Could you specify that for me? The machine has on board grafics now and some 8 to 10 PCI-e slots. Would have to open it to find out more precise.
What are the possible troubles this could cause?
Thx a lot guys.
The PCI-e slot standard has a few different physical sizes, but there is no rule that the large slots have to have the "full" complement of 16 PCI-e lanes to the cpu. A gaming motherboard may have 16 or 32 PCI-e lanes to play with, so to support 3-way SLI/crossfire, they may give the first full length PCI-e slot 16 lanes, and the other 2 full length slots 8 each. Or you may see a cheaper board go 8x 4x 4x if it only has 16 PCI-e lanes available.
But here's the issue - a single PCI-e lane is most likely "enough" for almost any card you could plug into a server mobo. A single high speed NIC, for example, may have a "short" pci-e connector blade and require only 1x PCI-e lane. So based on expected usage, you may have a server mobo a whole bunch of full-length slots and each slot may have only 1 or 4 pci-e lanes physically run to each slot, regardless of what size slot is soldered onto the mobo.
A modern video card can get away with 4x and show some slowdowns.
The bottom line is that you need to research the mobo and find out the PCI-e revision that is supported on the mobo, and how many PCI-e lanes are run to each slot. It may be far better to put a vid card into one particular slot, for example. Also, how many lanes go to each slot may be an option you can select in BIOS or with a mobo jumper. So you need the mobo specs and configuration information to know what slot would be best for a vid card, and how to get the most pci-e lanes assigned to that slot (if it is configurable).
Some gaming mobos change this on the fly, depending on how many video cards it detects upon bootup. I doubt a server mobo would be permitted to decide its configuration on its own at bootup so if it is even possible to bias PCI-e lanes to one slot, it is probably a bios option or set by a jumper on the mobo. To know for sure, you'll need to get the manual for that exact mobo and see.