Crosshair VIII Hero: upgrading to M.2 SSD, need advice on which slot to use

[Surebrec]

I am about to upgrade my OS drive to an M.2 SSD and would like some advice on which slot to use.

I've done my research, but the results seem to be conflicting. some people seem to insist that putting it in the top slot, whilst others say the bottom. is there a difinitve answer?

also, I am still looking for assistance with this issue:

https://rog.asus.com/forum/showthread.php?116776-Crosshair-VIII-Hero-Issues-with-RAM-speeds-and-boot...

[ATIXIUM]

I read some other thread awhile ago but can't remember to be honest however they mentioned it is best if it's closer to the RAM and CPU for best circuitry efficiency and cooling

[RedSector73]

bottom connected to x570 chipset
top is connected to cpu


I use the top.