I've heard from a few reviews of amazon users that any non Enterprise WD drive made in 2010 does not support any RAID Configs?
It's to do with the recovery timings established in the drive firmware. The consumer models (i.e. Blacks) have a
0,0 (read, write in seconds respectively), as the recovery is handled by the OS (disks attached to the ICH or a simple SATA controller card).
The enterprise versions have different timings (
7,0), as the recovery is meant to be handled by a RAID card (it takes over this function from the OS, as the card operates differently = necessity).
Previously, all a user had to do, was get hold of the TLER utility, and adjust consumer drives (this was common with Green versions for data center use, as there weren't any RE versions available in the past). This has now changed (when the RE4-GP came out), so they've now locked the firmware settings in the consumer models = forced to buy the enterprise models for RAID cards (REx or REx-GP), since it's no longer possible to adjust the firmware settings. They make more money this way.
The TLER utility will still work on the RE versions of the drives (no need to lock it here for profit reasons), as there may be instances where the timings may still need to be adjusted for stability reasons.
As per consumer disks and RAID cards, it won't be stable if you can even create the array (completes initialization), as disks will keep droping out (random).
But if the drive will be attached to the ICH (SATA ports included in the base system), then consumer units such as the Caviar Blacks will be fine, as they're not attached to a RAID card. The RAID functions are also part of the OS, located within Disk Utility.
So in your case, you'd be fine running the Caviar Blacks. If you go to a RAID card at a later date, you'd also need to get new disks (enterprise versions) for it, but the consumer disks can be used for backup purposes for example (i.e. run an eSATA card + Port Multiplier enclosure).
Hope this clears things up.
Non-Enterprise WD drives lack TLER, which makes RAID arrays stay together. Regular consumer drive will work from time to time, but they are not always 100% reliable.
Consumer disks are fine on the ICH or simple SATA/SAS card. But when a proper RAID card is involved, the timings aren't sufficient, and drop-outs occur (unstable as hell = massive aggravation, and possibly data loss if the backup was re-deployed with the same problem simultaneously).
To be honest, I've been using software RAID zeros with my Mac Pro and different WD drives that don't have TLER for more than a year now and never had a drive dropping out of the arrays.
With a hardware RAID controller, I totally agree that TLER enabled drives are the way to go, but the software RAID which is implemented in OS X seems to handle non TLER member drives pretty well.
Exactly for both cases. ICH or simple SATA/SAS card vs. proper RAID card respectively.
If your data is irreplaceable, then it's a very bad idea to run with RAID 0 in a four drive config with any brand of drive. The more drives you have in a RAID 0, the higher your possible failure rate is. At least you have backups...
With regards to the WD drives, I recall hearing about this sort of issue with some Seagates as well. Basically it's a bug on the firmware of the drive.
IF a user has a proper backup system in place, and can afford the time for recovery (fix the disks, restore the data from backups, and re-perform any missing work that occured between the most recent backup and time of failure), it's fine.
But in cases where the user's time is too valuable (can't spare it), then other levels (some form of redundancy) would be necessary.
BTW, no form of RAID can replace the need for a backup system (level doesn't matter; things can and do happen = data loss on the primary array).
Exactly, the cost of building a RAID 0 array is the same as buying a decent SSD and booting from it. Not only that, but you get a 99.99% reliability and much faster IO speeds.
Capacity requirements could matter here (i.e. need more capacity than SSD's could provide for say $200USD or so, and usage is primarily large files = sequential throughput dominant), but in terms of overall performance, I'd agree that SSD is a faster way to go, especially for random access throughput.
