Software we use requires disabling write-caching, but I cannot seem to be able to do so, either through Device Manager or through smb command line.
Does Optane not support the ability to disable write cache?
Thank you for posting in the Intel® communities.
The write-cashing feature cannot be enabled or disabled from the Intel® Optane™ Memory because the module doesn't work as a drive in your system. It will accelerate your drive, and it will be paired with it, but it will not work as a drive itself in your system.
Your drive and the module will be seen by the system as a new device, so the Intel® Optane™ Memory will no longer be visible.
I haven't tried this so I'm not sure if it will work, but what you can try to do is to disable the feature after the module has been paired with the drive. This is not recommended as it hasn't been tested or validated, but you can try and see if it works for you.
The following Microsoft* article explains how to disable the feature. It might be the same process that you already know, but I'm sharing it with you for your reference: https://support.microsoft.com/en-us/help/324805/how-to-manually-turn-disk-write-caching-on-or-off
I hope this information answers your concern.
Have a nice day.