Either of the M.2s will support an NVMe SSD, so there should be no difference between the two. 

depending on airflow of your case and which GPU you use, if using a blower style GPU card then use the bottom slot, get the EK m.2 cooler http://www.performance-pcs.com/ek-m-2-nvme-heatsink-nickel.html#!prettyPhoto those samsungs get quite toasty, i have the evo and with out any cooler or airflow it will idle in the 40's and hit high 60's low 70's under load. with the cooler on it i'm at 32 now with a high of 41c at full load. plus they look nice so use the bottom slot

 

albone
.....Thanks for the tip on cooling. A clip on heat sink for a M.2 SSD......what will they think of next?...I'm a cooling fanatic! so I'll order one.

there are a few on the market, the ek looks the best though and is the same price as the others, only thing is they are for single sided drives only, could probably make it work with dual sided but the stock clips wont fit

rjohnson11

quadlatte

albone
.....Thanks for the tip on cooling. A clip on heat sink for a M.2 SSD......what will they think of next?...I'm a cooling fanatic! so I'll order one.

there are a few on the market, the ek looks the best though and is the same price as the others, only thing is they are for single sided drives only, could probably make it work with dual sided but the stock clips wont fit

+1. Several motherboard manufacturers are beginning to include M.2 cooling solutions of their own.

they need to, they can get quite warm