Hello EVGA Fans,
 
I have looked for this specific question and have not found an answer.  I have the EVGA Z97 Classified and beginning a new build and I will be SLI'ing two GTX 980ti's.  In doing Forum research, I understand that the best install procedure is to use Slot 1 at x8 (CPU) and Slot 4 at x16 (PLX).  I would like to add a Samsung 950 Pro M.2 with an M.2 PCIe SSD - PCIe 3.0 4-Lane Adapter - not to be used as a boot drive but as a separate standalone drive to be loaded with games.
 
My specific question is with the above Slots used - what PCIe slot should I utilize (if able) to get x4 bandwidth to ensure I get the full speed from the 950?  As I understand it - Slot 1 is Native x16 tied to the CPU - if SLI is used, dropping it down to x8 - what other PCIe Slot is tied to the CPU as x8?  The diagram below annotates the remaining 4 PCIe Slots as PLX so I am thinking that any add-in card will drop the x8 (Slot 1) - x16 (Slot 4) SLI setup to x8 (Slot 1) - x8 (Slot 4) and x8 (x4 for the 950) in any remaining PCIe Slots.  Therefore - since there is not another PCIe Slot tied to the CPU - I will simply not be able to use the remaining x8 bandwidth.  Thank you in advance.    
 
   

 
Waiting for an EVGA tech to answer this one..  wish the i7-4790k CPU was 40 lanes not 16. :/
 
 

Thanks Nereus!  Yes, it would make SLI much easier if the i7-4790K had more lanes!  I had thought that the answer would be Slot 3 if even possible - but I am not sure - thus the original question. 
 
I am still waiting for an EVGA tech to weigh in.  In fact, I am still awaiting an EVGA tech to simply acknowledge the question.  I had an hardware issue with an EVGA product some time ago that cost me completely unnecessary additional money and time and so I took a break from EVGA for quite awhile with my other builds.  I usually Blacklist a company for life and steer others away in those kinds of circumstances, but against my better judgement I decided to give EVGA (a US Company) another opportunity to prove itself to a Retired Veteran.  I would be satisfied with a professional response regardless of the what the answer may be and currently I am still hopeful I will get an answer.  
 
Thank you in advance EVGA for your consideration.      

Hello, my recommendation would be use your cards in 1 and 4 and the SSD in 3.
 
http://www.evga.com/support/manuals/files/152-HR-E979-Part1.pdf on page 9 of this PDF you can see the lane breakdown, these are in all current generation manuals.
 
This is true on any of your 4 way boards that use 16 lane CPUs; PCIE slot 1 is form the CPU, if ONLY that slot is used then you will have 16 lanes form the CPU to that slot.  Now if you use any other x16 slot (meaning mechanical 16 not necessarily having that many lanes) 8 lanes are pulled from the CPU and provided to the PLX for replication.  Now the PLX will provide 32 lanes, 16 to the second and 4th PCIE slot.  Those will both be 16 unless you populate slots 3 or 6 which will divide the lanes available to 8 for slots 2 and 4 respectively.
 
TL;DR
I would do it like this:
 
PE1:  GPU (8x)
PE2:  Empty (8x form PLX)
PE3:  SSD (8x form PLX)
PE4:  GPU (16x from PLX)
PE5:  Empty (1x from PCH)
PE6:  Empty
 
SSD can go into 2 or 3 for the same performance, I went with 3 for better airflow if you are not water cooling.
 
I agree with the more lanes, Z chips imho should be 28, then  X series chips should be 40 for baseline and 64 for extreme editions.

 
 
 

So how would the Samsung 950 fit into the z97 classified?  I thought the m.2 slot was only a wifi m.2 slot

He is using an M.2 to PCIe x4 adapter. 

Do the adapters support UEFI?

Just remember that you wont get FULL speed out of the 950 from a Z97 as the PCI lanes are Gen2, not Gen3. Z97 uses four PCI-Express 2.0 lanes which run at 500MB/sec each. This will affect the speeds you get from the drive.

NO_sauce
Just remember that you wont get FULL speed out of the 950 from a Z97 as the PCI lanes are Gen2, not Gen3. Z97 uses four PCI-Express 2.0 lanes which run at 500MB/sec each. This will affect the speeds you get from the drive.

Actually, that is incorrect.  Any slot running from CPU or PLX will be running at PCIE Gen3, as a PLX only replicates at Gen3, also why they conflict with devices that are PCIE Gen2 only.  You will only get Gen2 if you are pulling from the PCH.