I use a PCIE Nand Drive as readyboost to improve my Windows 10's performance (and it does improve the performance drastically). The trouble is Windows recognize it as an internal drive instead of a portable drive, and therefore will pop out low storage notification.
I have follow the instruction found here: http://www.neowin.net/forum/topic/1264602-windows-10-disable-the-low-disk-space-warning/
Basically what I did is:
LowDiskMinimumMBytes DWORD 0 --> HKEY_LOCAL_MACHINE\Software\Microsoft\Windows Search\Gather BackOffLowDiskThresholdMB DWORD 0 --> HKEY_LOCAL_MACHINE\Software\Microsoft\Windows Search\Gathering Manager NoLowDiskSpaceChecks DWORD 1 --> HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
Unfortunately it does not stop the notification.