What is the difference between the two? I'm about to get either wd hdd RE or SE w/250 gbs and can't figure out which one is best for me.
Q: Regular 7200 RPM desktop drives run fine in RAID environments; why do I need these drives? A: Unlike regular desktop drives, WD RE SATA and EIDE hard drives are engineered and manufactured to enterprise-class standards and include features such as time-limited error recovery that make them an ideal solution for RAID.
Q: What is time-limited error recovery and why do I need it?
A: Desktop drives are designed to protect and recover data, at times pausing for as much as a few minutes to make sure that data is recovered. Inside a RAID system, where the RAID controller handles error recovery, the drive needn't pause for extended periods to recover data. In fact, heroic error recovery attempts can cause a RAID system to drop a drive out of the array. WD RE2 is engineered to prevent hard drive error recovery fallout by limiting the drive's error recovery time. With error recovery factory set to seven seconds, the drive has time to attempt a recovery, allow the RAID controller to log the error, and still stay online.
Q: Will these drives work with my existing power supply?
A: The WD RE SATA drive has the new 15-pin SATA power as well as the legacy 4-pin power connectors. (Do not connect both connectors at the same time.) The WD RE EIDE drives use the industry-standard 4-pin power connector.
Q: What about SATA connections? Is the drive hot pluggable?
A: The WD RE SATA works with latching SATA cables, non-latching SATA cables and SecureConnect™. SecureConnect is available only for WD SATA drives and provides additional structural support where the SATA cable connects to the hard drive. The WD RE drive is compatible with SATA backplanes and SATA hard drive carriers and, in those environments, is hot pluggable.
Q: For RAID environments I need SCSI data integrity.
A: The Serial ATA version includes 32-bit CRC error checking for all bits transmitted: command, data, and status. And, both SATA and EIDE versions include error checking to compare the data read back from the hard drive tob the data originally written to the hard drive.
Question
What is the difference between Desktop edition and RAID (Enterprise) edition hard drives?
Answer
Western Digital manufactures desktop edition hard drives and RAID Edition hard drives. Each type of hard drive is designed to work specifically in either a desktop computer environment or on RAID controller.
If you install and use a desktop edition hard drive connected to a RAID controller, the drive may not work correctly. This is caused by the normal error recovery procedure that a desktop edition hard drive uses.
When an error is found on a desktop edition hard drive, the drive will enter into a deep recovery cycle to attempt to repair the error, recover the data from the problematic area, and then reallocate a dedicated area to replace the problematic area. This process can take up to 2 minutes depending on the severity of the issue. Most RAID controllers allow a very short amount of time for a hard drive to recover from an error. If a hard drive takes too long to complete this process, the drive will be dropped from the RAID array. Most RAID controllers allow from 7 to 15 seconds for error recovery before dropping a hard drive from an array. Western Digital does not recommend installing desktop edition hard drives in an enterprise environment (on a RAID controller).
Western Digital RAID edition hard drives have a feature called TLER (Time Limited Error Recovery) which stops the hard drive from entering into a deep recovery cycle. The hard drive will only spend 7 seconds to attempt to recover. This means that the hard drive will not be dropped from a RAID array.
If you install a RAID edition hard drive in a desktop computer, the computer system may report more errors than a normal desktop hard drive (due to the TLER feature). Western Digital does not recommend installing RAID edition hard drives into a desktop computer environment.
right.The 16 MB model is the SE 16 - the SE is only 8 MB