But there are other tacks to honing a machine's overall efficiency. One approach is superior internal cooling technology. Companies, on average, spend as much on cooling servers as they do powering them.
The new HP ProLiant machines, for example, come equipped with a new feature that the company dubs "sea of sensors": 32 smart sensors that automatically monitor the heat created by the server and adjust fans accordingly. Employing sensors to adjust cooling at the datacenter level isn't new; bringing it to the server level, however, is, and it reflects just how significant a pain point cooling costs can be.
Dell too has been developing innovative approaches to cutting server cooling costs. Last year the company unveiled an innovative internal cooling design for its Power-Edge M-series blades. The system is designed to adapt to the needs of both high-end and low-end configurations. The chassis have three distinct cooling zones, each cooled by its own fan bank. In lower-end configurations where the chassis isn't fully loaded with blades, the fans on the side can run slower -- and, thus, consume less energy -- because they don't have to work as hard to cool their zone. In addition to its optimized fans (with underlying algorithms), the system boasts a superior airflow design. Dell managed this by removing impedance throughout the chassis.
Power supplies are also a major factor in the overall energy efficiency of a server. Here, vendors are taking different approaches. In the case of the new ProLiant series, for example, HP is offering customers a choice of four common-slot power supplies to meet their specific application requirements. The idea is that a power supply's overall efficiency varies depending on utilization. HP says these power supplies offer up to 92 percent efficiency on nearly all workloads.
In a related vein, Dell rolled out a 90-plus percent efficient power supply last year that it had developed in-house. According to the company, this power supply achieves higher efficiency at lower utilization levels. Most power supplies achieve their maximum level of energy efficiency only when the supply is running at 90 to 100 percent utilization. Alas, such is not the norm, as datacenters are notorious for running servers at very low utilization levels. Dell said its power supply is capable of achieving 88 percent efficiency at just 20 percent utilization.