Don't understand what chipsets/motherboards/CPUs allow for multiple GPU support at x16 3.0

CobaltImpurity

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Nov 16, 2014
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I'm picking parts for a gaming rig and wanted to have the option to get up to 2-3 GPUs all at 16x instead of having one x16 + 8x or something like that. So I was looking up what chipset I wanted and came across a chart on Wikipedia that shows that 1150 processors will only run one PCIe card at x16. When I checked what the 2011 page had to say about their best chipset could only run 2 at x16.

After reading this I recalled of the Asus x99-E WS board and that it can run FOUR cards at full x16. What, the **** am I missing here, because I'mp pretty sure the stuff i described in the paragraph above is incorrect.

On that note, I'd really appreciate an explanation for the difference between "40-Lane CPU" and "26-Lane CPU". I read on another forum post that it's how the CPU and GPU(s) communicate but I'm still kind of hazy on the details of how that actually effects the GPU(s) performance when you have too many cards and they start bottlenecking (if that's even correct).

Thanks!
 
Solution
Plx increases lanes as said and does increase performance to pretty much the same as having them. x99 would be your only modern chipset that does 3-4 x16 as long as it has plx. x16 is lanes which is 16 lanes but also they could be for other components that use pcie like m.2 or sata-e ports so you may not get all lanes the cpu has on pcie ports. You shouldn't worry about getting x16. There is just a negligible difference with x8. 5fps in best cases is hardly any and I'd understand if you got loads of money to waste but for most people, an extra $100+ for it is better spent on a gpu for a noticeable increase.
For the LGA 2011v3 processors, the i7 5820k only has 26 PCI-E lanes coming off of it. That means you can't do more than 3 way SLI with it effectively as SLI needs at least 8 lanes per card, and the 5820k can only provide 8 lanes to three cards. If you want to do 4 way SLI, then you need to get the 5930k or 5960x which has 40 PCI-E lanes. You still won't get the full 16 lanes for each card, but really at that point you're more likely to either hit a CPU bottleneck or run into scaling issues in the games you play before PCI-E bandwidth becomes a problem.

In practice right now, there is no bottleneck running cards with 8 PCI-E 3.0 lanes, even with the fastest cards on the market. There are no products on the market that are going to give you 16 lanes to all 4 cards in a four way SLI setup. Until Intel or AMD releases a CPU that has 64 PCI-E lanes coming off of it that's not going to happen.
 
Plx increases lanes as said and does increase performance to pretty much the same as having them. x99 would be your only modern chipset that does 3-4 x16 as long as it has plx. x16 is lanes which is 16 lanes but also they could be for other components that use pcie like m.2 or sata-e ports so you may not get all lanes the cpu has on pcie ports. You shouldn't worry about getting x16. There is just a negligible difference with x8. 5fps in best cases is hardly any and I'd understand if you got loads of money to waste but for most people, an extra $100+ for it is better spent on a gpu for a noticeable increase.
 
Solution