Hello, I recently picked up an X58 SLI LE board with the intent to run 3x GTX 260s in SLI. I didn't do as much digging into the slot wiring as I should, and when it arrived I realized the 4 x16 sized slots are wired x16 x8 x4 x8. I was hoping to keep 0 slot spacing between each card because the case I'm using won't accommodate a 2 slot tall card in the lowest x8 slot, which means running the third card in the x4 slot. I saw in the product manual that there were two 3-way bridges that came with the board originally. One for 0 slot spacing and one for 0 + 1 to allow for a single slot PhysX card between cards 2 and 3.
 
From my understanding, putting the third card in the x4 slot for 3-way would significantly hamper performance. Am I missing something? Why would the 0 slot spacing bridge be included if it was for a sub-optimal configuration? Or is it actually fine to run the third card in the x4 slot?
 
I don't have the 0 + 1 bridge or a single slot rear I/O panel to test, but I might pick up another bridge and just run the third card without a rear I/O bracket to test. If I can solve this ahead of time, though, that would be preferable.

bdary
The x4 slot was intended for something other than an SLI config.

For sure, that's what I figured from prior knowledge. I think the intent is for a dedicated PhysX processor. At least that's what contemporary reviews of the time highlighted as the use case. I'm just unsure then as to why EVGA included a bridge that would connect cards in the x16 x8 x4 positions, instead of only including the bridge that connects cards in slots x16 x8 and x8, which has more space between cards 2 and 3.

I dug through the posts and found a few relevant things:
 

• Someone running a 8800GTX in the x4 slot. Linked to a TechPowerUp article on PCIe scaling with a GTX 480. Noted an average performance hit of around 7% at 1920x1200 resolution.
  • X58 LE SLI: Would GTX 470/480 SLI get killed by 8x bandwidth? --> GeForce GTX 480 PCI-Express Scaling Review

 

• Also found this post asking about my direct use-case. It seems like the hit should be negligible.
  • X58 SLI LE TRI SLI GTX 260/216

 
I guess to answer my question about why the included a 0 slot 3-way bridge is because the performance hit should be negligible, at least on cards of the time. Saw someone that said x4 cripples performance for the GTX 260, but others say it's fine.
 
I'll run x16 x8 x4 for now to get the build finished, then do some performance benchmarks with the third card in x8.

Good to see you found some pearls of wisdom in those threads, that can help you on your SLI adventure
 
Happy to Help
 
Looking forward to reading your updates, in the future