Question about PCIe 2.0 x16 slots

[kr0490]

My motherboard has 2 PCI Express 2.0 x16 Slots. One blue, and one grey. The manual says the blue one is PC!e 2.0 x16_1 (blue, at x 16 link)

The grey one says PCIe 2.0 x16_2 slot (gray, at x 4 link)

What is x 4 link and x 16 link mean?

Thanks

 

[Leaps-from-Shadows]

The slots can be x16 physically, but have a varying number of actual PCIe lanes attached to them.

Your board has two x16 physical slots, but one has 16 lanes attached and the second has only four lanes attached.

 

[kr0490]

Does that mean if I got a second card for crossfire, one of them wouldn't be functioning at full capacity? I would be only gaining an extra fourth of power from it?

 

[Leaps-from-Shadows]

A board with one x16 slot with x16 lanes and one x16 slot with x4 lanes is technically capable of running CrossFire, but it's not ideal.

 

[kr0490]

Cause my board says right on it that it has crossfire support, so I never would have thought on of the PCIe x16 had only 4 links.

 

[kr0490]

I'm assuming since only 4 out of 16 lanes are connected, a video card connected to it would only operate at 1/4 of normal performance?

 

[Leaps-from-Shadows]

Cause my board says right on it that it has crossfire support, so I never would have thought on of the PCIe x16 had only 4 links.

Like I said in my previous post, it is technically capable of CrossFire with that config. If it's capable, the manufacturer will advertise it -- even if it doesn't work to the fullest.

I'm assuming since only 4 out of 16 lanes are connected, a video card connected to it would only operate at 1/4 of normal performance?

If the graphics card was powerful enough to actually use the full x16 bandwidth to its maximum, that might be correct. However, graphics cards are nowhere near that powerful.

Performance on your x16/x4 board will be reduced versus a board that can do x16/x16 or x8/x8 CrossFire, but the difference won't be that drastic.

 

[jaquith]

My motherboard has 2 PCI Express 2.0 x16 Slots. One blue, and one grey. The manual says the blue one is PC!e 2.0 x16_1 (blue, at x 16 link)

The grey one says PCIe 2.0 x16_2 slot (gray, at x 4 link)

What is x 4 link and x 16 link mean?

The difference is the x16 lanes are the GPU lanes and the x4 lanes are Data lanes and not meant for video lanes.

 

[kr0490]

So would it be cost effective to put another card in that slot?

 

[jaquith]

Assuming ASUS M4A88TD-V EVO/USB3 and AMD Phenom II X4 975 and (2) HD 6850 it's going to loose 'some' performance on the x4, and being wide eyed about it -- it will improve your performance but not ideally like on a x8/x8.

See this article -> http://www.techpowerup.com/reviews/NVIDIA/GTX_480_PCI-Express_Scaling/1.html

 

[kr0490]

Is it possible to use hybrid crossfire with my On board graphics and my radeon 6850?

 

[jaquith]

Your MOBO is Integrated ATI Radeon HD 4250 GPU with 880G chipset, and according to this chart -> No.

 

[kr0490]

Best answer selected by kr0490.