Hello! I'm a budding tech enthusiast who's still learning a lot of the technical details. I've been building computers for just a couple of years, but I want to know more about the components themselves. I'm have a new X99 build in mind, but I don't know a lot about the "PCI-E" lanes. It was brought to my attention that the 5820k has less PCI-E lane (capability?) than the other two x99 chips in the series. What does this mean basically? I do have an SLI configuration in mind, so will there be a bottleneck of any kind? Will I not be able to use 2 graphics cards AND a sound card, or a PCI-E SSD? Basically, how does it split up, and is the less PCI-E lane (26 instead of 40 I think?) rating an issue?

Thanks for any help in advance. Also, if you think this post belongs in a different forum (rather than General) let me know :)

You have x16/x8/x4/ and x1 lanes.  So if your CPU is capable of supporting 26 PCIe lanes, then let's say you have two GPU's.  When put in x16 lanes, they will run at x16/x8 (24 lanes leaving 2) or each at x8 (16 lanes leaving 10) depending on the slots you use.  Keep in mind that for SLI, both slots used must be a min of x8.
 
So you would subtract off how many lanes a device needs from your total available.
 
I'm not explaining it as technical as some other members might be able to, but this should give you the general idea of it.  Of course if your CPU is capable of 40 lanes, then you have that much more capability to work with.
 
Also, if your board has a PLX chip, that also adds some capability beyond the 26 lanes supported by the 5820.  There are pro's and con's to that.
 

 
Moving to General Hardware.

Whiplash88I'm have a new X99 build in mind, but I don't know a lot about the "PCI-E" lanes. It was brought to my attention that the 5820k has less PCI-E lane (capability?) than the other two x99 chips in the series. What does this mean basically

 
In essence, the PCI-E lanes allow the CPU (or chipset) to communicate with add-on boards and controllers (GPU, sound card, extra SATA controller, etc).  Typically, the X99 chipset will have 8 PCI-E 2.0 lanes, and the CPU will have either 28 (5820K) or 40 (5930/5960K) PCI-E 3.0 lanes. 
 

Whiplash88I do have an SLI configuration in mind, so will there be a bottleneck of any kind?

From what I've seen in the reviews, no.  Maybe the really top-end boards are getting towards bottlenecking on 8x PCI-E 3.0 lanes, but the benefit you get from SLI'ing them outweighs any bottleneck penalty.  I'm sure someone more knowledgeable than me in the individual boards will be able to provide some numbers. :)
 

Whiplash88 Will I not be able to use 2 graphics cards AND a sound card, or a PCI-E SSD? Basically, how does it split up, and is the less PCI-E lane (26 instead of 40 I think?) rating an issue?

It really depends upon the manufacturer and the model of the motherboard as to how they're split up, so you're going to have to look at the specs for the board you want.  For example, ASUS's X99-A has 3x PCI-E 3.0 16-lane slots, 1 PCI-E 2.0 16-lane slot (supporting 4 lanes only), and 2x PCI-E 2.0 1-lane slots.  With a 40-lane CPU, the first 2 GPUs get 16 lanes each, and number 3 will get 8 lanes.  With a 28-lane CPU, the first GPU gets 16 lanes, number 2 gets 8 lanes, and number 3 gets 4 lanes.  Just to complicate things, the M.2 slot shares bandwidth with the 4th PCI-E x16 slot, so you can only use one or the other (for either CPU type).
 
Does that help any?