apologies for the slight ignorance on some of the SLI considerations but I thought this forum would have some good knowledge and insight into my problem.  I currently run 3way EVGA 980s.  I am building a new machine and getting the X99 Classified mobo and dual EVGA Titan Xs.  The manual for the classified board says the following:
 
PCI-E Lane Distribution (40 Lane Processor)

PE1 – x16 (x8 if PE2 is used)

PE2 – x8

PE3 – x8

PE4 – x16 (x8 if PE3 is used)

PE5 – x4 (Gen 2 only, 4 lanes pulled from PCH)

PE6 – x8
 
My cpu will be the i7-6850 which has 40 lanes, so here are my ?s:
 
1.  To get best performance, should i be placing the two Titan Xs in PE1 and PE4 because they are both x16?
2.  If so, how do I determine whether the SLI bridge that comes with the X99 Classified (it appears there are 3 in the box) will fit versus having to order one from the gpu manuf?  What I am getting at here is the spacing between the slots and whether I'll end up having to use a different slot (than the 'ideal' one) because of the bridges that come with the mobo?
 
I know my ?s are rather stupid simple compared to some of the vast knowledge out here, so I appreciate your time in advance to help with my education.

thank you sir!  yes, they will be pascal so I think i'll get the new style bridge, if i do, i assume that will still be able to be bridged across PE1 and PE4, yes?
 
actually, since PE2 is farther away from PE1 than the rest are from one anohter, it looks like i will have the equivalent of 160mm between the SLI connectors (80mm from PE1 to the beginning of PE2, 40mm more for PE2 and 40mm more for PE3, ending up at PE4 for the second card).  What am I not getting, the 2slot spacing bridge you listed seems to only have 80mm, thanks for your time.

makes sense, thanks.  also, i read somewhere that new boards like this dont even need the bridge for sli capabilities, is that true?  if the board is doing x16 on both slots at the same time in SLI, what is the bridge getting?  i thought that the bridge added bandwidth that legacy boards wouldnt support (like if the sli slot was running in x8 mode or something slower than it wanted).  

hey cool, another ? for ya, it looks like using PE1 and PE4 prevents me from using the m2 PCI SSD slot for either the x99 Classified or the x99 FTW, am i interpreting that properly?

oh, so it lays flat, i thought it was going to plug 'in' into PE5 itself and stand upright.  i see what you mean that the lay down port shares pe5 so you couldnt plug into that also, but i was worried that my card would cover up PE5 and the ssd would not fit 'standing up'.  i see where i misunderstood based upon your explanation.  thanks for the reply.

Cool GTX
 
GPUs are  in PCIe 1 & 4 --> gives x16 speed, in both slots, with 40 lane processor

My Intel NVMe PCIe SSD is in PCIe 6 at x8 speed



If you run your GPUs in an x8 setup, performance May take a 3%-5% hit = 2 or 3 frame is my best guess.
 
 

Too bad this isn't true for everyone...