Review: WD10EACS 1TB and JJ-23VSUES

I just bought this disk and a second of these enclosures.
The disk is very quiet and reasonably fast, about 70%
of the current top performers, is my guess. I have reviewed
the enclosure before, it is an USB2.0/eSATA enclosure with fan.
Temperature is at 37C under load with 22C ambient.

While the JJ enclosure has been working fine for a while now with a
Samsung 1TB SATA drive, it has severe issues with the WD drive.
It has become inoperable several times in a short while, both
connected by eSATA and connected by USB, i.e. it is not a computer
issue but an issue of this combination of drive and enclosure.

In a different enclosure (Revoltec Alu Book 2.0) is seems to work,
although there are occasional command timeouts that the kernel (Linux
2.6.24.4) can recover from. Recovery attempts with the JJ enclosure
fail (the kernel does several before giving up).

My guess is that the Revoltec can handle the occasional timeout,
while the JJ controller cannot. This results in a "hard unmount",
i.e. the same as if the disk was pulled during operation. Potential
risks include filesystem corruption and data loss. And it is highly
annoying.

WD has been known to have occasional longer running commands or
timeouts, which originally prompted their Raid Edition drives.

My conclusion is that this is probably not an issue when mounting
the drive internally, but putting it in any external enclosure is
a risk and can result in unreliable operation or, in the worst
case, in a basically inoperative combination. Using this drive
with a RAID controller may or may not be problematic.


Chipset JJ:
JM20336 SATA, USB Combo
Chipset Revoltec:
Sunplus Technology Inc. USB to Serial-ATA bridge (ID: 0x04fc/0x0c15)


Arno