16x or 8x

[peugot]

hi, i watched a video about SLI with a 28 lane and a 40 lane processor. from what i can understand it looked like the 28 lane would put 2 cards in 8x + 8x which would be stupid, it is enough lanes to run in 16x + 8x right ? is there a way to find out what they are running in my system because this affect me with my 5820K that have 28 lanes and i use SLI? tnx

 

[Lochekey]

Gpu-z will show you what your cards are running at. In all honesty though unless you are benchmarking you will really not see a difference between 8x and 16x.

 

[EarthDog]

Exactly. ^^

You lose 1-2% performance with 8x/8x.

 

[peugot]

Exactly. ^^

You lose 1-2% performance with 8x/8x.

it looks like i am running 8x-8x :/ can i in any way force it to run one of them in 16x tho ? tnx for the replies btw

 

[EarthDog]

Nope. As I said, barely any losses anyway.

https://www.techpowerup.com/reviews/NVIDIA/GTX_980_PCI-Express_Scaling/21.html

 

[wingman99]

PCIe Lanes - PCIe 8x vs 16x in SLI

 

[peugot]

PCIe Lanes - PCIe 8x vs 16x in SLI

hehe, this is the video that made me think about it. even if there is not much difference i still want the absolute max i can get from my system you know, since there is free lanes anyway

 

[EarthDog]

Not possible unless the board has a PLX chip. That said, there is additional latency with using a plx chip so it's kind of a wash.

 

[JrClocker]

I have an MSI board (not the same one), but they are very specific about which slots will give you x16 and x8. If you have a card installed in one of the other slots, the main x16 slot will go to x8.

Did you check the MSI forums for the optimal slot configuration for SLI? They actually have a map for my motherboard that shows what happens with the PCI lane switching when you have cards installed in the various slots!

 

[cdawall]

Nope. As I said, barely any losses anyway.

https://www.techpowerup.com/reviews/NVIDIA/GTX_980_PCI-Express_Scaling/21.html

There is zero loss between PCI-E 16x 3.0 and PCI-E 8x 3.0



Unless you run AMD then you loose an entire percent.

 

[EarthDog]

The OP is running at 4K? I missed that.

EDIT: I see his sig has 5760x1080 and 4K. The higher the res, the less loss it seems (though that feels a bit counter intuitive).

 

[cdawall]

The OP is running at 4K? I missed that.

EDIT: I see his sig has 5760x1080 and 4K. The higher the res, the less loss it seems (though that feels a bit counter intuitive).

4k was as close as I could get to "3k" like the op is running. Point was there is next to no loss.

 

[peugot]

okay thank you people, then maybe i should just save the extra lanes for a raid card that i want anyway