WD DLG diagnostic checked discs (Extended Scan) all ok.
On closer analysis, the Intel Rapid Storage Technology BIOS ROM is indeed quite old, dated December 2010, whilst these Series 6 Intel sandy Bridge chipsets - B3 revision - have been re-released only a few months ago.
I believe Intel is overdue to update the RAID BIOS ROM option; in fact, they have released updated versions for their own motherboards and I have read of modding attempts to port the new IRST ROM option to other BIOSes.
Not to mention that the one and only reason for the recall and release of the B3 revision was - in fact - a problem with SATA ports!!
Intel has a legal and commercial obligation to provide the same updates to other manufactures - such as Asus - so they can too include the updates in their own BIOS revisions. If they already have, then we need to know, so we can put pressure on Asus to release the new BIOS.
The problem could quite possibly exist between the newest SATA3 HDD and the Intel 67 chipsets.
Afterall, these new Western Digital SATA 6Gb/s Caviar Blacks are "tested and recommended for use in consumer-type RAID applications" (quote from WD Caviar Black literature). Hence the buck stops with Intel: chipset and RAID controller must be made fully compatible with these expensive high performance disk drives.
Any one from Intel care to comment?
i'm a bit in late and with a very strong headache (and two nights passed wout to sleep) due to the same problem... but i could find the solution!
My array, any array, results degraded after a cold reboot (hard reset)... and almost always the first drive (not a drive in particular but always the one connected to the first sata port)... but entering IRST config menu the hard drive came back! ****!
The problem is the boot up of the mainboard is too fast and the IRST boot rom is inovoked too early when the disks r not fully spinned up (i'm using 4 big Hitachi 3TB) and so not ready yet to be detected by IRST... Here is the reason that always the disk, connected to the first SATA port, is missed... cause it's the first one (in time) attempting to be detected by IRST... It's also the reason that rebooting the machine wout turning it off it doesn't give any problem (yes, of course, all the drives r already ready!)
Now how to workaround the problem?
Sure it would be better to ask ASUS to increase the delay in the invoking IRST boot rom or at least to put an option in bios to set this delay. Ok, it's already present in bios a delay for post screen (settable in seconds) but it's referred to the second post screen, the one that appears after IRST boot rom (already too late!)
Here how i could workaround the problem:
1) Insert any additional controller raid card (even cheap) in any slot. The rom of this additional controller will be invoked before than IRST boot rom, giving the time to the disks to spin up fully and to be ready when IRST attempts to detect them.
2) In alternative u can set up the USER password in BIOS. Doing so, when u turn on the pc, the password will be prompted u first. So just the time to type the password and all ur disks will be already ready to be detected by IRST.
Try to believe!
Milan - Italy
Many thanks for your insights. After lots of searching I found your note. I seem to have the same problem -- will take a while with more cold reboots to verify. But I have some peace of mind now. FYI, I wrote this all up in a new post (May 2015) -- so maybe someone else will find the same information useful. FYI, Dell Optiplex 755's with two RAID1 in an Intel IRST mirror, running Windows 7. Very nice machine. Here is the reference:
Again thanks so much. BTW, are you going to the Milan Expo?
John in Canada