Idle Power Consumption
Idle consumption is the most important power metric for consumer and client SSDs. After all, solid-state drives complete host commands quickly, and then drop back down to idle. Aside from the occasional background garbage collection and house keeping, a modern SSD spends most of its life idling. Enterprise-oriented drives are more frequently used at full tilt, making their idle power numbers less important. But this just isn't the case on the desktop.
We previously established that Samsung's 840s are the king of idle power use, and that continues today. By comparison, Intel's SSD 525s fall to the middle of the pack. Take those numbers with a grain of salt, though: they're almost certainly affected by the mSATA adapter we're using to test.
The big mushy middle of this chart is dominated by SandForce-driven products. The controller company is working diligently on getting idle power down, but the fruits of its labor aren't going to be seen for some time.
It's also worth pointing out that capacity doesn't really affect idle numbers much. Instead, it's almost completely a function of the controller and firmware.
PCMark 7 Average Power
If we measure average power use through a run of PCMark 7, we're able to observe a more taxing workload. These measurements fall far lower than maximum power numbers, despite the benchmark's intensive nature. What does a log of consumption look like?
The peaks and valleys correspond to the individual sub-tests. An average consumer workload might look a lot like this, except the distance from peak to peak would be greater, representing more sporadic use throughout a day.
That helps us explain why the bar chart of average power consumption in PCMark 7 looks so much like the idle power use chart. Despite the myriad spikes during the test, average draw is far closer to idle. Even if a drive is power-hungry under load, the averages don't look so bad. Some of these SSDs might use up to 6 W. But even the worst-looking model we've benchmarked, OCZ's Vertex 4, consumes a reasonable 1.49 W during PCMark 7.
Four of the SSD 525s pull up equally here. Only the 240 GB model falls a bit lower in the finishing order.