Well, my 9260 card can't spin drives down with any new firmware. I have to use 2 year old firmware in order to have spin down (so called "dimmer") option. Recently I decided that it might be a good idea to upgrade firmware on my server (LSI 9260-4i card). Update went smoothly, I rebooted and everything is great. To my shock 24 hours later I see that none of my drives are sleeping. I checked power options and see that only hot spare and drives that are not allocated can be span down. Option for active drives is gone. This is what I found on LSI site: 16590, What are the types of MegaRAID Dimmer Switch power savings settings, and should I use any of them? There are three settings for LSI MegaRAID Dimmer Switch power savings: From the User Guide: Dimmer Switch I (DS1) - Spin down unconfigured disks. This feature is configurable and can be disabled. Dimmer Switch II (DS2) - Spin down Hot Spares. This feature is configurable and can be disabled. Dimmer Switch III (DS3) - This new feature spins down any Logical Disk after 30 minutes of inactivity, by default, if the array can be spun up within 60 seconds. This feature is configurable and can be disabled. DS1 and DS2 are okay to use. DS3 should not be used, and has been disabled on newer versions of LSI MegaRAID 9260/9280 RAID controllers. In some cases, when Dimmer Switch with DS3 spins down the volume, the volume cannot spin up in time when I/O access is requested by the operating system. This can cause the volume to go offline, requiring a reboot to access the volume again. I think that it's ridiculous that such a great option to save power is completely disabled. My guess there is an issue with controllers and they decided to disble that option completely. I wish I knew that they can screw cutomers in such a way.