On a Product Level
Now that you have decided on your technologies, which particular components and models you want to use for your PC, you should reconsider knowing that there are some components which can be selected individually, in pairs or even in larger quantities. Memory is a perfect example, as every desktop system and even an increasing number of notebooks are based on dual channel memory layouts to increase bandwidth. Two memory modules are used to achieve this, but while the effective performance increase is only small, there is a measurable increase in power consumption. That said, memory choice can be considered important if you have found ways to reduce power consumption for most of the other components.
Hard drives may also be configured into arrays, which create one storage partition using several drives. Multiple solutions based on RAID technology can be used to achieve this; the more sophisticated RAID modes even require stand-alone controllers. For desktop PCs you will typically use RAID 0 to increase throughput—striping works much like dual channel memory, but with the option to deploy multiple drives—or RAID 1 to mirror all data onto a second hard drive.
If you want maximum data safety you have to go with RAID 1. In this case you can still analyze whether or not you need the capacity and performance of 3.5” hard drives, or if you could use 2.5” hard drives. These smaller drives, which can be found in most notebook solutions, require only a fraction of the power of 3.5” desktop hard drives, though they also offer limited performance and capacity.
Also think of consolidating storage. If you plan to move two older hard drives into your new PC, why not purchase a larger hard drive, which can store all your data, instead of spending power on two or three drives?
Finally, you can save the most power if you go for a notebook instead of a desktop PC entirely. This consideration may be too far to go for the average user who is reading this article in order to find advice on how to optimize energy efficiency, though. Notebook components typically have a much reduced power consumption and better energy efficiency than desktop devices, but that comes at the cost of flexibility, performance, and at much higher cost for the entire system.
On an Operating System Level
All modern operating systems support power saving mechanisms to shut down individual components after a certain period of inactivity. Hard drives can be spun down, monitors shut off or the entire PC put into suspend mode or even into hibernation mode. Hibernation is effectively like shutting the system off; when it powers up it simply loads the operating system state from the hibernation file on the hard drive, rather than launching the operating system from scratch.
Your power saving mode (balanced, performance, power saving) will have an impact on processor speed, given that processor drivers are installed and CPU power saving features were enabled in the BIOS. AMD’s feature is called Cool’n’Quiet, while Intel named it Enhanced SpeedStep.
Once the operating system is aware of all of its power saving tools, it can contribute to minimizing power consumption.
