The HS-251 uses one of the new Bay Trail CPUs, and it looks to be the ideal choice. As a multimedia-oriented NAS, the unit comes with 2 GB of RAM, but you unfortunately can't expand its RAM total should you need more. Yet even XBMC, a resource hog, will work nicely with just 2 GB.
|QNAP HS-251-2G Specifications|
|Processor||Intel Celeron J1800 (Bay Trail), dual core|
2.41 GHz with 2.58 GHz Burst Freq.
22 nm, 10 W TDP, 1M L2 Cache
|Operating System||Embedded Linux|
|Memory||2 GB DDR3|
|Storage||2x 3.5"/2.5" SATA III|
|RAID Levels:||Single Disk, JBOD, |
RAID 0, 1
|Capacity||up to 12 TB (disks not included)|
|iSCSI||Target & Initiator|
|Networking||2x 10/100/1000 Mbit Ethernet|
|Additional Connectors||2x USB 3.0, 2x USB 2.0, 2x HDMI* |
*(currently only one is active)
|Dimensions|| 302(W) x 220(D) x 41.3(H) mm|
11.89(H) x 8.66(W) x 1.63(D) inch
|Power Consumption||HDD standby: 8.96W |
In operation: 15.64 W (with 3 x 3TB HDDs installed)
|Power Supply||External, 60 W, 100-240 V (DPS-60PB)|
| Price excluding VAT|
(at the time of the review)
Up to two HDDs or SSDs can be installed, and we think most of you will find the 12 TB of combined storage space two WD WD60EFRX drives provide to be enough. There is no support for RAID 5, 6, or 10 since the NAS only takes two drives, but we doubt such RAID levels would prove useful in a multimedia NAS. Cooling requirements would also increase with more than two HDDs, which would probably result in a larger unit and a fan to keep operational temperatures at acceptable levels.
The unit has two Gigabit Ethernet ports, which gives users the ability to combine these for higher transfer speeds or use one as a fail safe. The rest of the I/O is comprised of four of USB 3.0 and USB 2.0 ports, each, and an HDMI output. There is unfortunately no eSATA port, but we believe the USB 3.0 ports to easily fill the void. Our only complaint is that all ports are at the rear, which makes reaching them difficult.
Mostly due its low height, the NAS is fairly compact. The latter will prove incredibly useful since it allows you to place the NAS nearly anywhere inside your living room. Because of its compact dimensions, QNAP had to use an external power brick, which is strong enough with its 60 W maximum power output. By placing the PSU outside of the NAS, QNAP also got rid of a heat source, which makes the fanless design more effective. The unit is pretty pricey compared to other two-bay NAS servers of the high-end category, but the HS-251, as you will figure out by reading this review, hides more than meets the eye, though QNAP could have at least increased its warranty to three years.