I am about to upgrade my system to a 7820x CPU with the x299 FTW K.
 
My question is about the M.2 slots. I plan to use a Samsung 960 Pro 1TB and an Intel Optane 900p 280GB. I plan to install the 960 in the lowest M.2 slot and put the 900p in the first M.2 slot under the primary video card (an EVGA 1080 Ti). The 960 will be my boot drive and the Optane for games. What concerns me is that the manual only mentions M.2 Optane support on the 80mm M.2 slot, the one in which I wish to install the 960. I feel the 960 should not be under the GPU so they don't share heat and cause the 960 to throttle. Installing the Optane M.2 to U.2 adapter under the GPU would make more sense to me for that reason.
 
Are there any issues here or will this work okay? Thank you!

I want to put the 960 in the lower slot because otherwise it will be under my 1080 Ti and 960s are known to run hot. I don't want the 960 over-heating.
And no, this is the Optane drive I have: https://www.newegg.com/Product/Product.aspx?Item=1Z4-009F-00053&cm_re=900p_280-_-1Z4-009F-00053-_-Product
Since I cannot use the onboard U.2 with the CPU I have, I am going to use the M.2 to U.2 adapter to connect it to the other M.2 slot.

I had not really taken into account the distinction between Optane as a "system enhancer" and just a drive. When you put it that way, I think you are right. Why would it not work the same as any M.2 drive?
Thanks for the perspective.

Which CPU are you using? A 28 lane SkylakeX or the 16 lane KabbylakeX?
 
Have you checked to make sure there is clearance between the bottom of the GPU and the motherbaord for getting an M.2 U.2 adapter in there?
My other thought was an PCIe U.2 card - only thing that I could find on newegg was this - https://www.newegg.com/Product/Product.aspx?Item=N82E16815158437&cm_re=U.2_PCIe_adapter-_-15-158-437-_-Product
 
Not sure how well (if at all) it would work with your drive
 
In reality you would have been better off getting the one that I linked - it was $20 cheaper
 
Not sure how many games you plan on installing - 280gb (un formatted) is not going to get you very far these days
Just looked at my 500gb Game Drive SSD - used space - 419gb and that is not my full Steam / Origin library
 
If you have not bought any drives yet I would suggest putting https://www.newegg.com/Product/Product.aspx?Item=N82E16820147596 into the top M.2 and use the thermal pad that comes with the FTW on the bottom side of the 960 - make that your OS / Boot drive. Put the planned 1tb 960 drive into the 2nd slot for your games and other soft ware. If it is just OS and virtual memory running on the top M.2 who cares if it gets a little warm. That is my planned drive setup, but I have an X299 Dark with that nice m.2 cooler :P
 
 
 

As stated above, I have the 7820x which is a 28 lane CPU which is why I cannot use the U.2 slots.
 
I am using these two drives because I already have them. They were used separately before but I plan to rid my system of the remaining SATA SSDs and go full NVMe.
 
By games I really just meant an MMO or something. I was speaking generally because my specific use is irrelevant to the question.
 
And yes, I am aware it has two M.2 slots. I am just trying to decide which slot to connect each device to. I thought it mattered because of something I misunderstood in the manual.

I was running asrok motherboards with up to 3x m2 drives and sli 1080ti's never gave much thought or felt concerned about their temp (m2s). Under heavy workload (if you'll be using them in such way) the temps can go above 100C, but if youre gaming I doubt they will be used to such extent.

rjohnson11
One alternative you may not have considered is to buy two M.2 NVMe SSDs and put them in raid as opposed to using Intel Optane. The X299 FTW has 2 M.2 NVMe slots. 

yep that be for my c drive2 960 raid 0 on a classified board


 
 

Fredski
I was running asrok motherboards with up to 3x m2 drives and sli 1080ti's never gave much thought or felt concerned about their temp (m2s). Under heavy workload (if you'll be using them in such way) the temps can go above 100C, but if youre gaming I doubt they will be used to such extent.

 asrock could not take a stable 5k but the classified could with the same CPU but i would not recommend it keep it over clocked to all core 4.7 and your have a stable system that rocks with the EVGA  classified but get a good water cooler for it my choice is thermotakes floe