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.    
 
   

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.      

 
 
 

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

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.

EVGATech_DaveB

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.

I see I could have read your previous post more carefully where you explained this already! Haha. So the limitation for z97 is when running 4 way SLI? I have some reading to do on this. Thanks for catching my mistake.

cdc-951
So if I was to get a Intel 750, run it in the 1st slot I am assuming since it is native to the cpu pcie lanes? Also if I had 2 980 ti's cards, where should I place these 2 cards?
 
Will they all run at full speeds?
 
Will I run at Pcie 3.0 on the ssd and all cards?
 
 
lastly if not would the 2nd card run at x8 and the 1st card run at x16
 

Here is the slot breakdown for the Z97 Classified.
 
PCI-E Lane Distribution

• 
  PE1 – x16 (x8 if PE2 is used)

PE2 – x16 (x8 if PE3 is used)

PE3 – x8

PE4 – x16 (x8 if PE6 is used)

PE5 – x1

PE6 – x8

 
So in essence, PE1 is fueled by the CPU and its 16 Lanes.  The PLX chip will take 8 lanes from PE1 leaving it with 8, and those 8 are used for lane replication, giving 16 lanes to PE2 and PE4.  Both PE2 and PE4 share their lanes as needed, (much like the 2 primary slots on the FTW board which only supports 2x SLI due to no PLX) if PE3 is populated both PE2 and PE3 will get 8 lanes, and if PE6 is used then PE4 and PE6 both get 8 lanes, PE5 is pulled form the PCH and is as such 1xc of Gen2 and is in effect completely removed form lane allocation for this discussion.
I hope that clarifies the function of the lanes and PLX.
CPU lanes are ALWAYS faster (similar bandwidth, but no PLX latency) but PLX does allow 3x and 4x SLI on boards that would otherwise have no means of supporting them.  So for optimal setups it is always best and fastest to use the least PLX, however, PLX can, not always, but can argue with SSD's and other devices.  So for optimal speed I would run the cards like this:
PE1 - GPU1
PE2 - empty
PE3 - empty
PE4 - GPU2
PE5 - empty
PE6 - SSD
And if this gives you problems try this configuration instead:
PE1 - SSD
PE2 - GPU1
PE3 - empty
PE4 - GPU2
PE5 - empty
PE6 - empty
 
Hope this helps.
 
**edit for formatting issue**

None of the speed differences will be large, but Slots 1 and 4 were tested as the fastest solution for 2 way SLI.  So when possible I would go with that, I made the compatibility suggestion as sometimes SSDs don't like PLX slots, if that is the case run the setup with the SSD in the top slot.
 
On an unrelated note, I dig the Hornet avatar :)

By the cards running faster, in testing engineering tested 2x SLI in slots 1&2, 1&4, and 2&4, although 2&4 technically had more lanes, it was ALL PLX so there is some latency to deal with, 1 and 4 gave the best performance.  Now a additional PCIE device will likely skew that some, but I think the baseline will persist.  The performance was measured with benchmarks like 3D Mark and Heaven  and Valley.

Dear EVGA Fans,
On my 4SLI configuration and using PCI Ex Lanes  only for Graphics, I am Running x8 - x8 - x16 - x8  for each respective
PCI Ex 3 Lane, Is the Card No3 Running x16 not the one sitting on the No.1 slot, should I remove monitor HDMI Cable to the
No3 Card? 
Is it true that only No1 card / Slot  delivers Video?
 

athanassiosmakriniotis
Dear EVGA Fans,
On my 4SLI configuration and using PCI Ex Lanes  only for Graphics, I am Running x8 - x8 - x16 - x8  for each respective
PCI Ex 3 Lane, Is the Card No3 Running x16 not the one sitting on the No.1 slot, should I remove monitor HDMI Cable to the
No3 Card? 
Is it true that only No1 card / Slot  delivers Video?
 

For this board it should be 8 - 16 - 8 - 8.  This is normal and is a byproduct of PLX replicated lane routing.  As for where to plug in your monitor, it is completely irrelevant, it will not effect anything.  No it is not true that only slot 1 delivers video.  But there is ZERO impact on performance from plugging your monitor into a different card.  They are all part of the same SLI setup.

EVGA,
 
I am attempting to post an update in this thread; however, have been getting this error message for days:
 
An unexpected error occurred and logged. Please try again later.
 
Can you please fix this issue so further posts can be made for the EVGA Community.
 
Thank you.
 

That is strange.  Strictly speaking, everything should be working as intended at this point.  Have you manually set the PCIE speed for the slot the SSD is in to Gen3, I know it is detecting as that, but that is a setting it can't hurt to try as it sounds like you have a false positive somewhere.
Also, to rule out some conflict with the PLX, can you try the SSD on the top slot?
Lastly I have not tested that combo, nor do I have the adapter here to test with.  I can check with our engineers to see if they have, but I have not nor has anyone else I know personally.  I was advising based off of specs and how things SHOULD work.

Can both of you try it in the top slot and see if you have the same speed issues, also make sure the PCIE is set to Gen3 manually in BIOS as well?
That is the only Gen3 slot that is not run by a PLX chip, I am thinking this might be a issue form that.  Either way that will be more information I can send to the engineers.

Dave B and EVGA,
 
I would first like to thank Nick for his valuable input which verifies that there is an issue with the implementation of M.2 drives as recommended by EVGA.
 
I neglected to mention that as part of the trouble-shooting procedures, I did force Gen 3 for the PCIe slots in the BIOS which resulted in no change to the M.2 speeds.
 
The good news is that I installed the M.2 drive in PE1 as suggested by Dave and the results were outstanding!  My link speed is now 10Gbps and my Sequential Read speed is 2600 MB/S.  This is even slightly better than the M.2 drives rated speed.  (Attachment 1 and 2)  Thoughts on this Dave, EVGA?
 
I have now installed my GTX 980ti’s in PE2 and PE4 for the time being and I am monitoring the card’s temperatures.  I am getting 16x/16x as expected instead of 8x/16x which will be unnoticeable but it is nice to have the max speed possible.  The plastic fan shroud of my top video card was literally in direct contact with the metal backplate of the bottom video card.  These backplates get EXTREMELY hot and will literally burn you when they are running at full load.  I unscrewed the mounting brackets for both cards allowing the bottom video card to hang a bit lower and rigged the top video card to raise it slightly.  This allows about 3/8 inch clearance between the two cards.  Not optimum of course but better.  If you are water-cooling two video cards, you will not have this issue.  Since I am not moving the computer around, this should be ok but it is certainly a bit more strain on the PCIe slots.
 
As a test run, my temperatures of the video cards at idle (Celsius) are 56 top/40 bottom.  Gaming is 83 top which is the max and 59 bottom.  Obviously a large difference between the two due to the lack of proper spacing between the cards and this is with a 140mm case panel fan blowing on the cards.  In addition, I am still experiencing boot problems at times where the PC will not boot the first try as it is looking for a boot drive and resetting the PC allows it to boot the second time.
 
I will continue to monitor and weigh whether this M.2 drive is worth the increase of GPU temperatures over the SSD RAID array already in this computer as well as the boot problem.  For my current configuration, is there any way PE2, PE3 or PE6 PCIe slot can run the M.2 at full speed...10Gbps...with maybe a BIOS update?
       
In closing, please excuse me for being somewhat forward but from a customer’s perspective, it seems like I was troubleshooting EVGA’s product for EVGA.  I purchased the M.2 drive as a result of the information provided by EVGA which appears to have been incorrect and one would think that information would be passed by EVGA engineers to their customers instead of the other way around.  EVGA has many more resources with their own motherboards, power supplies, video cards, etc. than a customer and certainly should have the most knowledge of their own products.  Perhaps erroneously, I was envisioning a lab at EVGA to trouble-shoot hardware and products like my company’s IT department.  As customers of products and services themselves, I’m confident that this is understandable by EVGA.  Again, just honest feedback from a loyal customer.
 
I would like to sincerely thank Dave for his assistance in troubleshooting as well as his promptness in his replies.  I will provide any important updates/issues to this setup if they should arise to assist my fellow EVGA fans.
 
Thank you again EVGA!