NVME Controller Configuration GEN 10 ML 110

[hythemr]

I installed a NVME PCIe adapter with a NVMe drive for my boot drive.  I also have 4 drives in Raid 1 on the SR100i array.  All is working to a degree, but Enabling cache and other settings for the NVME are not available in bios.  
My question is in the bios -Storage Options- Sata Controller options- Embedded Sata Configuration- Is currently set to Smart array sw raid support if I switch that to Sata ACHI will that only affect the NVME or will it clear my array as well?  Thanks in advance.

[rpronk]

The SR100i is the sofware solution that utliizes the onboard SATA connections. So yes disable that and your RAID arrays will no longer function.

The NVME PCIe adapter isn't related to the SATA options in your BIOS. If it doesn't pop up as a separate entitiy (under PCIe devices) the bios won't allow changing settings for it. 

[hythemr]

Yes, NVMe settings are minimal in the bios. I am able to set write cache in device manager, but it automatically disables it every restart. The raid settings are set for write cache, so Im not sure what setting is turning it off every restart?

[rpronk]

Assuming that "device manager" indicates you are using Windows, "write cache" is then just your normal RAM.

Why would you want to enable write caching on the NVME drive anyways? NVME is super fast, so why put it in memory first?

A hardware RAID controller can have separate (battery backed) memory for write caching, which can give a (large) performance benefit when it needs to write to spinning disks.
That's a very different use case then what you are trying to achieve.

[hythemr]

Correct Server 2019.  With write cache on I'm getting Over 3,000 MB/s Write, with it off I'm getting 587 MB/S Write.  For our SQL database it does make a noticeable difference.  On our Sr100i array drives we only have documents and backup files so write and read speed doesn't make a real difference in daily use.

[rpronk · Accepted solution]

I'm not a Windows sysadmin, but perhaps your server is also an AD controller?

See https://social.technet.microsoft.com/Forums/en-US/44b943d4-93f2-47f5-af75-1f554627d59c/server-2016-raid-writecache-policy-disabled-after-reboot?forum=ws2016

Assuming you are aware that enabling write caching puts you at risk of data loss on crashes and power outages.

[hythemr]

Correct again, we do have a UPS battery backup on the Server, but I believe you figured it out.  Thank you.