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.
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Each board does have a 16x PCI-Express slot for a riser card but these have been nullified by the additional SIMSO+ remote management controllers included in the price. The cards fit in a mini-PCI slot and have a header card, which provides a backplate with dedicated network management ports. The cards incorporate a Raritan chipset, which delivers full KVM over IP and remote browser management facilities.
The management web interface is a tidy affair that provides good levels of data about all motherboard sensors, which can be linked up to email alerts. Virtual boot devices are supported as are remote power controls and you also get full server remote control included as standard - a feature HP still only offers as an option on its iLO2 management solution. You can also access each management controller using Supermicro’s IPMI View 2.0 utility, which offers up a dashboard of dials on temperatures, fan speeds and voltages, controls for recycling power and performing graceful server shutdowns and also remote control access as well.
There’s more as each server can be locally or remotely monitored via the SuperO Doctor III utility, which provides plenty of operational information on all critical system components. Remote control options are more basic as you can only access the power settings, but this does enable you to access the server from another system, gracefully shutdown the OS and control power.
The Janus II is looking good so far but no doubt the burning question is whether it delivers on its power promises. With it connected to our in-line power meter we saw the entire system drawing a modest 23W with both servers powered down. With one server fired up and Windows Server 2003 R2 idling along the meter registered 94W and with both servers pottering along this rose to 159W. We then ran SiSoft Sandra simultaneously on both servers and with this pummeling all sixteen cores to the max, consumption peaked at 312W.
Our test results were noticeably higher than those quoted by VeryPC but it’s worth putting them into context. We ran the same tests on another Supermicro 1U rack server with a pair of L5320 Xeons, 4GB of FB-DIMM memory and eight SFF SATA hard disks and saw it draw 22W when powered off, 182W in idle and 250W under extreme load. A similarly equipped HP ProLiant DL360 G5 was also measured at 30W when powered off, 213W in idle and 310W under load. Both these figures are under the power draw for the Janus, but offer half the processing cores.
The GreenServer Janus II is a unique rack server solution that offers some distinct advantages. On the downside the power supply is a single point of failure so a UPS is an essential buy and the 30GB capacity of the solid state disks won’t go far, but getting two servers for little more than the price of one has got to be a good deal in anyone’s book.
Author: Dave Mitchell
VeryPC GreenServer Janus II