It's difficult to find any info or specs on the power consumption of optical disk drives, does anyone know of any review sites that test ODDs for power efficiency? For 5.25" desktop size all I could find was this old review on Tom's Hardware: 2007 comparison. One review doesn't tell us much.

I wonder if newer desktop drives are now more efficient, particularly at idle. Do these things 'sleep' like inactive HDDs? I don't think it will be possible to use slimline drives in the desktop systems I am building, though an external USB drive might be an option for one of them, but there isn't much in the way of power consumption data for those either.

Anyone done their own testing or know of more recent reviews?

I too can only think of external USB drives as the power requirements of optical drives tend not to get published.

Basically, you're on your own. This is typical for almost all pre-2008 hardware. There was simply no interest at all in power consumption. Historically, because of systems integrators needing thermal data, CPU power dissipation has always been known pretty accurately but all the other components were rarely specified and almost never measured in reviews. It's a last-couple-of-years-thing.

My experience is that in general, slimline optical drives and optical drives that have direct slimline brethren (e.g. optiarc AD-7700S and AD-7260S) usually have low power consumption, because the slim drive is supposed to be used in laptops. Optical drives at the beginning of a new era, e.g. earlier blu-ray drives, are horrible in this respect.

One aside: optical drives have ridiculously high power consumption peaks. Peak consumption on my multimeter read about 30W for an AD-7260S. If you're planning on using a PicoPSU, an optical drive is almost impossible to use (unless you go for one of those 150+W power adapters, which are a waste of money).

Not just new optical drives but old ones as well. I have my tower very close to my right ear (on top of desk) the optical drives are all level with my head and less than a foot away. I can hear every little sound they make.

They are powered down 99% of the time or more. I notice them on boot and when I access a disk. Other than that they stay powered down.

I can say that behavior was normal even with the old 6X DVD drive made in 1999 all the way up to new lightScribe DVD writers made in the last few years.

Now how loud they are during spinup and reads is another story but at idle they don't make any noise or use much if any power.

Laptop optical drives have a lower speed rating which should further reduce maximum power consumption. When idle, I doubt either kind would use more than a watt or two. I measured mine at slightly under a watt.