IT Pro Verdict
The innovatively designed GreenServer Janus II offers two servers for close to the price of one. With only one power supply between two motherboards, obtaining external power redundancy will be an absolute must and the 30GB SSDs are of very limited value, but the GreenServer Janus II does deliver a good specification for the price and has a genuinely modest appetite for power.
In the search for ever more energy efficient servers vendors are having to be more innovative and VeryPC's latest GreenServer Janus II delivers a unusual solution. It may be a 1U rack server but this compact box is endowed with no less than sixteen Xeon cores and yet claims to offer extremely low power consumption.
You might assume that the Janus II uses four Xeon MP processors, but you'd be wrong. In fact, it contains quad-core Xeon 5400 series processors. To achieve this feat the Janus II is actually two servers in one chassis. The system is an all-Supermicro affair, which uses two of its proprietary X7DCT motherboards. Apart from the shared power supply they deliver two completely independent servers.
The front panel gives little away but closer inspection shows that it has two power buttons and indicator panels. Supermicro is one of the last server manufacturers to embrace the smaller 2.5in SFF hard disk form factor but it's paid off with the Janus II as the front panel has room for up to eight hot-swap SFF drives. These are split between each motherboard with each having four bays apiece. There's no room for optical and floppy drives for each server so you'll need to source USB models.
Removing the lid reveals two separate motherboards running the length of the chassis with the shared power supply module located between them. Each board comes equipped with a pair of 2.5GHz Xeon L5420 processors. These are of the low power variety with a TDP of only 50W. Intel's 5100 is the chipset of choice and each board sports an embedded Intel four-port SATA controller, which supports RAID0, 1, and 5 arrays along with hot-swap.
One backplane looks after all the hard disks but each motherboard is wired through to its own set of four bays. VeryPC's choice of storage is clearly designed to cut power consumption but it will not be to everyone's taste and does limit the server's capabilities. Instead of standard 2.5in SATA hard disks, VeryPC has only installed a pair of 32GB solid state drives. These will undoubtedly drop the power draw but the miniscule 30GB of storage for each server is simply not enough for everyday use.
Overall internal design is particularly good with clear access afforded to all components. The power connectors for each motherboard are located right next to the power supply outputs so there is virtually no cable related clutter to mar this perfect symmetry. All eight SATA cables are present and correct and neatly routed around the boards. The motherboards are designed to maximise the air flow effects and there's room for three dual rotor cooling fans in front of each one. However, the lower heat output of the Xeons has enabled VeryPC to drop the number of cooling fans for each board to only one.
For the network connection you get a pair of Gigabit ports for each server but there's no room for further expansion. However, Supermicro does have other versions of this motherboard design with the INF model offering an embedded Mellanox InfiniBand controller with a 20Gbps port at the rear. Alternatively, you could opt for the X7DCT-10G model, which presents a single 10GbE CX4 port as well as dual Gigabit.
