Computers can get pretty small, but that doesn't mean they don't know to draw down a whole lot of power. Laptops and desktops both need to draw fuel from somewhere, and sometimes, the amount of electricity being pumped through your PSU is a lot more than you'd think.
 
Whether you want to lower your hydro bill, or reduce your carbon footprint, lowering the load inflicted by your Mac or PC is a great place to start. While it was once taken for granted that PCs required a lot of power, these days we know differently. With a greater interest in power saving and conservation, users have devised some interesting ideas on how to lighten their electrical load. Some are fact, and some are fiction, and the hard part is knowing which is which.
 
Today we're going to debunk some power-saving myths and lay down the cold, hard truth.

Claim: Using Dark Wallpaper and Screensavers Conserves Power

There was a time when people believed that Google's homepage was actually wasting us all energy. White, some argued, was actually harder for most computer screen's to display, and black-heavy background would save us all a great deal of power. The problem is, that only holds true for older, CRT-based displays. As Google so eloquently stated in a blog post on the situation, "on flat-panel monitors (already estimated to be 75% of the market), displaying black may actually *increase* energy usage." Ouch. 
  
Verdict: False

Claim: An Idle Computer Uses Less Power

Some people believe that leaving a functioning computer on all night will consume just as much power as it does during the day. For the most part, however, this isn't exactly true. Most operating systems now incorporate a variety of power saving functions that tone down your power consumption when not in use. Hard drives can be set to spin down into an idle state, network functions disabled, USB devices put to sleep, and on some laptops and desktop machines, even have the CPU step down to a lower clock speed. All of these together can help to greatly reduce the power consumption of an idle machine.

Verdict: True

Claim: Hibernation Is Better Than Standby

Standby, as everyone knows, puts your Mac or PC into a low-powered state, with just enough juice to keep your data in RAM. Hibernation, on the other hand, dumps this data to your hard drive, allowing power usage to be cut almost completely. Or so you'd think. Both modes cut power consumption to only a few watts, but the actual difference is almost negligible. In fact, the difference between hibernation and standby isn't as much about power reduction at all, but data safety and state persistence.

Verdict: False

Claim: Cycling The Power On/Off Uses More Energy Than Constant Uptime

The saying goes that each time a computer is cycled off, and then on again, it consumes more power than simply leaving the computer on. In some ways, this is partially true. A regular boot process includes polling USB devices, accessing hard drives and handling network traffic — all heightened activity that might not occur constantly when fully booted. However, as we explained above, the relatively low-power idle process of most modern computers is more than enough to make up for this ever-so-slight bump in usage, meaning you can probably cycle that power button as much as you wish.

Verdict: False

Claim: Solid State Drives Consume Less Power Than Conventional Platters

Common knowledge dictates that SSD's are not only fast, but great at reducing power consumption, improving your battery life in the process. Considering what we know about hard drives, this conclusion seems to make sense. SSD's, after all, have no moving parts compared to their platter and head-based predecessors. However, Tom's Hardware has done a great job at proving that this is simply not true. While a typical hard drive has varying power requirements, depending on how much the drive head must move across the platters, SSDs do not. They are either active, or idle.

To put it simply, "They will draw their maximum power level constantly when in use, and as a consequence, simply spend more total time drawing maximum power than conventional drives." As a result, some manufacturers have begun to include power-saving capabilities in certain drives — the trick is finding one with the feature.

Verdict: False 
 
Images via Flickr users Rakesh Ashok and hongiiv.