I've got a RS2WC080 connected to 8 4TB SATA III WD Black drives, on an Asus Z9PE-D8 motherboard. It's set up as RAID 5 with all the disks in a single volume.
The problems I'm having are twofold: first, it disconnects whenever the OS sleeps. Meaning that when it wakes up the virtual drive has unmounted and Windows can't find D: drive any more. This machine is being used as a workstation, and I'm not keen on having it running all the time without sleeping.
The second is that the write performance is really bad. Like 45Mb/s, when the read speed is in the mid 700s. I followed the performance guide here: http://www.intel.com/support/motherboards/server/sb/CS-029227.htm Server Products — Configuring Intel® RAID Controllers for optimal performance or tried to, because a lot of the options - like setting write cache policy to 'Write Ahead' and read ahead policy to 'Adaptive Read Ahead' - don't seem to be possible, either in the RAID BIOS utility or in the Web Console.
Any pointers on what I might be doing wrong?
Other specs: 2 x Intel E5-2690 x 10 cores @ 3GHz, 64Gb RAM, Windows 7 64-bit.
Unfortunately unexpected RAID drop is not an unusual case when the RAID is set with drives, which do not have the TLER (Time Limited Error Recovery) technology. The WD Blacks are great drives for gaming and performance, but talking about RAID configuration they are not highly recommended. Don't get me wrong, they can work well, but it is highly possible to give you errors. Desktop edition drives require longer error recovery time, which may exceed the expected time from the RAID controller, causing the RAID to drop. I presume that your RAID is working fine, if it does not go to sleep, which is totally OK, but if an error occurs and the WD Blacks take a bit longer to recover, you may experience the same RAID drop. I leave you more information about different WD drives.
Talking about Read/Write speeds, the performance may depend of different factors, from the selected RAID type, to the controller and the PC configuration. I would wait for the community to share some experience with RAID5 and see if what you're getting is normal or not.
http://wdc.custhelp.com/app/answers/detail/a_id/1397 http://wdc.custhelp.com/app/answers/detail/a_id/1397 – difference between Desktop drives and RAID drives
Hope this helps