Dear Sir or Madam,
the Intel RSTe driver seems to have a bug which prevents drives that are part of a RAID array to spin down after a certain idle time.
I tested with all drivers from 3.5 up to 4.3 and with different OS from Win 7 up to 10 Pro. If I use the Win 8.1 or 10 integrated driver, HDD spin down works fine, but if I install any RSTe driver, it no longer works for drives in a RAID (tested with RAID 1 and 5). Single drives still power down though, really odd behaviour. However, the integrated Windows drivers are based on the normal RST drivers, e. g. 13.x in WIndows 10. This might explain why it works with these drivers, obviously these normal RST drivers do not seem to have this issue (besides the 14.x series which also does not spin down correctly, see here: https://communities.intel.com/message/317473#317473)
Is this a known issue? When will be a solution available for that? This is really annoying as it causes heat, noise and reduces the lifetime of the affected hard drives in a 24/7 environment if they are running although they are not accessed over hours. Moreover, the power consumption of large arrays (I have a RAID5 with 4 drives) can easily be 10-20W that can be saved if the drives power down correctly. Please fix this bug!
Best regards
Stefan