LGA775 motherboards and PCI-E slots

[notepad]

I'm probably going to buy an LGA775 board, and have a general question.

Many (most?) desktop motherboards for sale now seem to have 1-2 PCI slots, 2 PCI-E x16 slots, and 1 or more PCI-E x1 slots. Are there any known motherboards that will not run any cards other than graphics in their x16 slots?

I will be running a single x16 PCI-E video card, and a x4 PCI-E card in the other x16 slot. While this should generally work, I've heard that at least one or two early PCI-E SLI motherboards will not run anything but video in their x16 slots (somehow). I'd like to avoid that, or know if that even occurs anymore with current mbs.

Thanks.

 

[GhislainG]

You should verify the compatibility of the x4 PCI-E card with the manufacturer. Why an SLI motherboard if you don't plan on using more than one video card? Why not buy a P45 based motherboard? That's what I did because they could support up to 16GB of memory and most have a second PCI-e x16 slot that runs at x8 and can be used for a RAID controller.

 

[roofus]

well he doesnt specify SLI. there are so many boards with 2 or more PCI-e slots now he could be talking about any of them lol. ghi is correct though. look at the specifications for the board you are intrested in. i wouldnt get an Nvidia chipset unless my intent was SLI though.

 

[notepad]

Thanks for the replies.

I don't plan on running SLI, but many boards nowadays have two or even three x16 slots, but don't specify they are for SLI. From the sounds of it, as long as the board doesn't state it is specifically for SLI, I would probably be fine with 2-3 x16 slots.

 

[GhislainG]

An Asus P5Q Deluxe is based on an Intel P45 chipset. It provides three x16 PCI-E slots and up to 16GB of memory. I use one to run Windows Server 2008 and several VMs and it has been very stable. Unless you need SLI, you should probbaly stay away from NVidia chipsets. Only Nvidia chipset based LGA775 motherboards are SLI capable.

 

[notepad]

So it seems that some Nvidia chipset motherboards that state they support SLI will tie the two x16 slots together in the circuitry in some fashion, so that you cannot use a non-video card in the second slot.

I'm wondering, do the Intel chipset boards that support Crossfire do the same things? I've found some boards with 2 x16 slots (or one x16 and one x8), but with Crossfire support. I'm not sure how this is done (outside of some of it being in the driver) and don't know if it locks down the second slot for video only usage.

For example, this board:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128369

Searches are failing me on this question; even downloading the manual for the motherboard in question doesn't help. Since it's a weekend, I doubt a support ticket would be answered before Monday (and due to a failing component, it looks like I'll need to move faster on this build than originally expected).

The Asus P5Q3 Deluxe is certainly one I'm keeping my eye on, but I'd like to be able to cross-shop.

 

[GhislainG]

Do you really require a motherboard with DDR3 memory?

Crossfire and SLI mean that you can support at least 2 video cards. Since you plan on using a single video card, why are you so concerned by SLI or Crossfire support?

Either an NVidia or an Intel based motherboard will work, but quality motherboards based on Intel chipsets tend to be more stable. The Asus P5Q3 Deluxe (DDR3) or Asus P5Q Deluxe (DDR2) will definitely do what you want, but what is the PCI-E x4 card that you want to use? It's very important to ensure compatibility.

 

[notepad]

My concern with SLI/Crossfire is just that I want to make sure that if a board has 2 x16 slots, the second can work with a x4 controller card.

Most motherboards seem to either have 2 x16 slots and SLI/Xfire support, or only one x16 slot and a bunch of x1 slots. Since I need a slot for a x4 card, I need a board with x4 or higher to support it.

I'll be getting an Intel chipset board, probably P45.

 

[GhislainG]

An x16 slot will accept x1, x4, x8 and x16 PCIe cards. As an example, I can run the following PCIe cards in my P5Q Deluxe with 3 PCIe X16 slots:

Slot 1 (blue) max. x16 link
Slot 2 (black) max. x8 link
Slot 3 (black) max. x4 link

That's why I bought it.