The TeraStation Duo is a two-bay version of the TeraStation III and is Buffalo's highest performance dual-drive NAS aimed at business users and offered in 1 and 2 TB flavors. The TS-WX1.0TL/R1 model we tested came with two hot-swappable Samsung HD502HI EcoGreen F2 500 GB drives, configurable in JBOD, RAID 0 and RAID 1 arrays. The drives are hot-swappable, but RAID migration and expansion are not supported.
Like the Tera III, the Tera Duo uses a Marvell MV78100-A0 C080 Single-core ARMv5TE-compliant Feroceon clocked at 800 MHz. In fact, the Duo uses the same board as the Tera III, except the Marvell 88SX7042 SATA II controller has been removed. The CPU is mated with 512 MB of soldered-on-board RAM and 512 MB of flash. Dual Marvell 88E1118s provide two Gigabit Ethernet ports that support independent, redundant, auto-failover and multiple aggregation modes with 4, 7 and 9 K jumbo frames support.
Two USB 2.0 ports can be used for USB flash and hard drives for expansion or backup and print serving. UPS synchronization is supported via a single serial port and a second serial "factory use only" port provides Linux console output.
Power consumption measured 16 W with the two Samsung drives. Fan and drive noise are low, meaning the NAS is slightly audible in a quiet room. Three shutdown / startup schedules are supported, which reduce power consumption to 9 W. But, as we found with the Tera III, the idle disk spindown feature did not work.
CIFS/SMB, AFP and NFS network file systems are supported, and files can also be accessed via FTP and secure FTP. HTTPS is supported for admin access. Up to eight Distributed File System (DFS) links can be made to other Tera Duos or Tera IIIs.
Media features include iTunes and UPnP AV / DLNA servers. There is also a BitTorrent-certified download client.
Immediate and scheduled backup can be done to an attached USB drive or other networked Buffalo NASes and the Tera Duo can also serve as Apple Time Machine storage. Backup, performance, however, is about half that of other current-generation NASes, measuring only 8 to 10 MB/s (depending on drive format) backing up to a USB RAID 0 array. Network backup to a Buffalo LinkStation XHL was faster at almost 17 MB/s.
A single license for Memeo Windows / Mac OS client backup software is bundled. The Duo, like the Tera III, also supports remote, secure file access via BuffaloNAS.com or directly via HTTPs.
The Tera Duo currently ranks at the top of our RAID 1 NAS Charts. RAID 1 write performance with a Gigabit LAN connection averaged 56.4 MB/s for file sizes between 32 MB and 4 GB, with cached behavior not included in the average calculation. Read performance was very similar, measuring 56.1 MB/s with the same conditions. File copy performance using a Vista SP1 client under the same conditions (RAID 1, Gigabit LAN) measured 31.5 MB/s for write and 50.7 MB/s for read.
Since the Duo's features are virtually the same as the TeraStation III's (except for RAID 5 and other features related to four drives) there will not be a full review. See the Tera Duo's slideshow and consult the Tera III's review for further details. Don't forget to compare performance (including backup) using the NAS Charts.