Data Centers cooled with air int he conventional fashion have fundamental restrictions on power density. Generally this cannot exceed 150-200 Watts per square foot. A rack on a standard foot print of 16 sq ft cannot handle more than 3.2kW on average due to multiple factors. Adding a rear door does improve things considerably as power per rack can be increased safely to about 15-20kW. Above this, recirculation and back pressure cause at the bottom of the rack to overheat. Care must also be taken to block any vacant slots and to ensure pressure balance. If one or more servers’ fans are idling and others at full speed then air might blow back through the idling servers, degrading the overall cooling performance.
The Exablade has none of these restrictions and can be packed very densely. No specialized building is required. In addition to the reduction in overall expense an organization is not burdened with a large, slow to depreciate property which can have certain tax advantages in some jurisdictions.
As demonstrated on the Energy Comparison page most savings arise from applying Clustered’s advanced cooling system but there are also additional savings from the power train and applying I/O virtualization.