I've had an issue with my setup and after some investigation have decided to post it here.
My setup is as follows:
Motherboard: ASrock Z68 Pro3-M
SSD: OCZ Agility 3 90GB (Latest firmware, 2.15)
HDD: 2x WD Caviar SE 160 GB (SATA2, 16MB Buffer)
Intel RST version 10.8.0.1003
The HDDs and SDD are configured as in the following image:
That is: SDD split into 65 GB Data volume (for OS) + 20 GB Cache volume (for SRT), HDDs in RAID1 array, accelerated with Enhanced mode.
After a day of heavy writing on the RAID array (installing and restoring all main applications and data after installing my OS on the SDD) I have started experiencing slow speeds on the array. After a bit of trial and error, I'vedecided to start HD Tune in order to check the reading speed on the array. This is the result:
As you an see, reading speed is about 0.9 MB/s During this whole time, I could hear the HDDs struggling to read. That is, a few seeking noises, then a pause, then some spinup. Rinse and repeat. The same could be said about testing access time... it would be populated a bit, then halt, then populate some more, etc.
I went to the Intel RST control panel and deactivated acceleration. Everything went back to normal:
I activated it back, ran the test - same results (0.9 - 1 MB/s read speed). Deactivated - read speed normal. I then reactivated it and rebooted the computer. Now it behaves normal, with acceleration activated (that is - everything back to normal after reboot).
I will take note to see how to reproduce the issue in the future.
It has happened to me again though not as severe as the first time - it seems to be tied with resuming from S3 sleep somehow.
EDIT: Happened again, this time I'm sure it is because of putting the computer to standby for a longer time (overnight)
Are there any logs that could provide more insight or some steps I can take to change this behavior?