Rising global energy costs and an increased energy consumption of 2.5 per cent in 2011 are driving a real need to combat server sprawl through increased capacity and higher frequency memory modules to meet server needs for on-demand scaling at lower power. 
Figure 1. World primary energy consumption 
Figure 2. Typical power used by office equipment 
As shown in Figure 2, servers are typically the biggest power consuming computing platform in an organisation due to their increased processing performance compared to a standard desktop computer or portable computer.
Server component configuration, therefore, plays an important role in reducing power consumption while still meeting increased client computing demands. 
Figure 3. System average power consumption 
Managing the power consumption of a server requires a component-level breakdown as shown in Figure 3; we can then identify the memory component as being the third highest consumer of power. 
To combat rising energy costs and reduced power allowances, companies are scrambling to consolidate servers to efficiently utilise their multi-core processor architecture and large-memory-addressing capabilities by operating servers at their peak performance 24 hours a day, 7 days a week and 365 days a year through virtualisation.
Balancing target memory allocation, host memory over- commitment per virtual machine versus the efficiency at which those resources are then utilised and most importantly, at what cost to the company, impacts the server Total Cost of Ownership (TCO) and overall Quality of Service (QoS) to clients. 
By obeying the three rules below, we can easily reduce power usage while increasing capacity to meet scaling demands in new or existing servers
1. Fewer DIMMs (Dual Inline Memory Modules) use less power – when possible, install the least amount of DIMMs to reach your application memory capacity needs.
2. Quad-rank DIMMs have a lower power usage per Gigabyte (GB) than any other DIMM type.
3. Configure the server to drive memory frequency at the slowest permissible frequency for additional power savings.
To understand exactly how the consumption of power scales on newer generation servers using DDR3 technology DRAM (Dynamic Random Access Memory), the following results have been compiled for analysis.