It looked for a while like the promise of blade technology was about to give way to the hard economic realities of rising energy costs, but a slew of new developments seems to have placed them back on track.

Blades were the darlings of the data center earlier in the decade as the need for more processing power in limited physical space was in high demand. However, as the decade progressed and attention started to shift from overall processing power to "watts per square foot," blades' dense configurations and high heat factors started to raise some eyebrows.

Now, new virtualization and networking techniques are putting some luster back into blades as enterprises are clamoring for high-performance and even portable data centers.

Verari Systems, for one, recently introduced a new blade solution for VMware ESX 3.5 environments that the company says doubles the number of partitions on a single blade even while cutting power consumption in half. The VB1257 for the BladeRack 2 XL platform sports quad-core Xeons and can hold up to 16 virtual machines, cutting more than 50,000 kilowatt hours than if those machines resided in their own dedicated server instead.

New blade efficiencies are leading some firms to finally embrace them after gamely sticking to rack-mounted devices for so long. Rackable Systems just announced that it will include IBM's BladeCenter devices into its ICE Cube modular system, aiming the combination at remote and rugged installations. The advent of blade technology into modular data centers could accelerate their deployment as quick solutions for everything from disaster recovery to cloud computing.

Networking support is also vital for blade infrastructures, as performance depends not only on the individual blade, but how well they work together. BLADE Network Technologies recently unveiled a new 10 GbE L3 switch for the NEC SigmaBlade that provides a unified fabric for virtual and converged workloads. The device offers four 10 GbE uplinks and 16 10 GbE interconnects to other blades, providing up to 400 Gbps of total switching capacity. The company also introduced a 1 Gb L2 switch.

With both the power and cooling drawbacks finally getting some serious attention, it's hard not to imagine that blades will become the de facto technology for new and updated data centers. From both a capital and operational perspective, they'll be pretty tough to beat.