Solid-state hard disks don't help battery life

the other issue with their totally undocumented test, is that they don't tell you what the operating system setting are for drive power down--on an SSD with effectively zero "spin up" time, i dont see any reason to set this value higher than the operating system's minimum, which should give you some really serious power saving with minimal if any impact on usability.

Hey Rob, please update the article a bit with the concerns shown in the comments here man.

Since this was performed under a Windows machine, this isn't exactly correct for Macs.

Windows accesses the hard drive constantly and less efficiently than a Mac. OS X uses way less hard drive resources than the standard Windows machine. This article is flawed.

Whats the difference between IDE / ATA / SATA / Solid State ?

I saw links to buy hard drives on the right. I was so shocked by the article I just had to buy seven.

Just thrown away thousand bucks for that on my macbook air... life sux ! sure I can get a hit with that one ... http://lifesuxdaily.com

Damn right "optional".

The sad thing is this will now become the "conventional wisdom" despite its inaccuracy. Me, I want cheap space. SSDs can't deliver that yet. I can buy a 320gb 2.5" hard drive for my MacBook for $130 from NewEgg. You can't even by SSD units over 64gb right now (or have the 128gb units shipped?) and they cost around $800-$900. I don't care what kind of power savings might be associated with SSDs; any money I might save in energy costs will be more than overwhelmed by the initial outlay for the drive. That 320gb drive might eat up more energy over its lifetime, but its overall price will still be lower than the SSD.

I hope SSDs will eventually come down in price and expand in capacity to where they CAN be viable hard drive replacements for mainstream users. The MacBook Air and its Windows-based brethren might represent the first steps toward that goal. In the meantime I'll keep using physical disks.

Copied from a post on Engadget:

I'll be less vague than Bob. The TH article was, as usual, significantly flawed. The benchmark they used to test battery life restarts itself after each completion, doing so until the battery is dead. However, the article did not report how many times the benchmark was able to run on the SSD vs. the mechanical HD.

The reason this is a critical flaw is that, as their own graphs show, the performance of the SSD was substantially better than the other HD. With a slower drive, the CPU spends a larger proportion of time in idle mode, as the system is blocking on IO, waiting for the slow drive to return data.

With the faster SSD, the CPU spends less time idling. It is using more power, but also doing more work. If TH had reported the number of times the benchmark ran on each machine, we would have seen the SSD machine run the benchmark many times more than the mechanical drive. Their conclusions are flat-out wrong.

The whole exercise was very silly to begin with. An SSD draws less power in use than a mechanical drive does while idle. Of course it will improve, or at least not effect, battery life. The article you reference is just another sad example of the decade-long slump Tom's Hardware has faced.

Aye, the hard drive is often the slowest part of the computer. If the CPU has to spend more time idling waiting for data (therefore decreasing power draw), then it's gonna look like normal magnetic hard drives are better for battery life.

A solid state hard drive is better for battery life BECAUSE it gets data to the CPU faster, thus the CPU can idle faster. For those that don't know, CPU's take up much more power than hard drives ever will.