Container vendors often tout 40 percent to 80 percent savings on cooling costs. But according to Sams, "in almost all cases they're comparing a highly dense [container] to a low-density [traditional data center]."
Containers also eliminate one scalability advantage related to cooling found in traditional data centers, according to Sams. Just as it's more efficient to cool an apartment complex with 100 living units than it is to cool 100 separate houses, it's more cost-effective to cool a huge data center than many small ones, he says. Air conditioning systems for containerized data centers are locked inside, just like the servers and storage, making true scalability impossible to achieve, he notes.
Gartner analyst Rakesh Kumar says it will take a bit of creative marketing for vendors to convince customers that containers are inherently more efficient than regular data centers. Gartner is still analyzing the data, but as of now Kumar says, "I don't think energy consumption will necessarily be an advantage."
That doesn't mean there aren't any advantages, however. A container can be up and running within two or three months, eliminating lengthy building and permitting times. But if you need an instant boost in capacity, why not just go to a hosting provider, Kumar asks.
"We don't think it's going to become a mainstream solution," he says. "We're struggling to find real benefits."
Kumar sees the containers being more suited to Internet-based, "hyper-scale" companies such as Google, Amazon and Microsoft. Containerized data centers offer scalability in big chunks, if you're willing to buy more containers. But they don't offer scalability inside each container, once it has been filled, he says.
Container vendors tout various benefits, of course. Each container is almost fully self-contained, Rackable's Noer says. Chilled water, power and networking are the only things from the outside world that must be connected to each one, he says. Rackable containers, which can be fitted with as many as 22,400 processing cores in 2,800 servers, are water-tight, fitted with locks, alarms and LoJack-like tracking units. Sun's Modular Data Center can survive an earthquake -- the company made sure of that by testing it on one of the world's largest shake tables at the University of California in San Diego.
A fully-equipped Rackable ICE Cube costs several million dollars, mostly for the servers themselves, Noer says. The container pays for itself with lower electricity costs due to an innovative Rackable design that maximizes server density, Noer says.