Enabling write back cache - H710P, Server 2012r2

 

I run a T320 here at home, configured as follows:

Supplied H310 card runs 2 SATA drives in a RAID1 (OS drive)

A second H710P card runs an 8-disk array (RAID6), and it's this card I'm interested in.

The box does file/print for our home network, plus some basic media services, and it also has a few VMs running, for various purposes - not overly heavily loaded.

I've noticed a fair bit of disk thrashing and in checking the H710P's settings, it's write cache is set to write-through. I'd prefer to set it as write-back, to leverage better performance out of the array. However, when I check the OS' settings for the array's assigned drive, it is set to write-back...

I'd have thought that the controller would control the disks under-pinning the array completely independently of what the OS was doing, but am wondering what - if any - "interaction there is between the OS' cache policy, and that set for the controller itself.

Obviously, the H710P has a (healthy) BBWC, and the Server itself has two redundant PSUs, each plugged into a different UPS, so performing cached writes in the event of a power outage and gracefully shutting down the machine shouldn't be an issue...

Do I disable write caching within the OS, and set write-caching "on" on the controller, or...?