Power consumption of idle floppy and CD/DVD drives?

**anon** · 01.02.17, 06:16

On a desktop computer, what's the power consumption of floppy and optical drives when they're idle (no media inserted and motors not running)?

The online answers I've found are either inconclusive or contradictory, with DVD rewriter estimates going from 0.1 to 20 W, for example.

**Master Razor** · 01.02.17, 08:23

estimates going from 0.1 to 20 W

Impossible. An 3.5 7200RPM HDD goes up to 14W when in full load/100% usage and takes 0.4W when in idle which is still in usage.

Logic would dictate that an unused piece, that is never accessed, would need to take 0.1W to 0.2W. Same for CD-ROMs and Floppies.

**anon** · 01.02.17, 19:50

Originally Posted by Master Razor

Logic would dictate that an unused piece, that is never accessed, would need to take 0.1W to 0.2W. Same for CD-ROMs and Floppies.

It depends on what the power consumption of the circuit board that remains active is, but I was also thinking of those numbers.

And come to think of it, external USB 2.0 DVD rewriters can't draw more than 2.5 W. Even though they're the same low-power (and low-speed) ones used in notebooks, idle consumption on a desktop can't be much higher than that, if at all.

**v6ph1** · 01.02.17, 23:47

Don't be so sure with the 2.5 W for USB drives:
Many of them - especially 3.5" HDD and optical drives works outside the specification.
From lwn.net

The floppy drive consumes about one half Watt of power, so the savings are small. But big savings can come from many small cuts, so the device was left unplugged. The Asus CD-S500/A CDR drive was tested, it consumed about 1 Watt of power. The Sony CRX320E DVD-RW drive was tested, it consumed about 2 Watts of power.

Or you may have a look at this Samsung Spec - site 9
10mW to 3.5W

For DVD drives exist a test at TomsHardware

The most power consuming components are the motor and the lasers - so the idle consumption should not be that high.

-- v6ph1

**anon** · 02.02.17, 07:10

Originally Posted by v6ph1

Don't be so sure with the 2.5 W for USB drives:
Many of them - especially 3.5" HDD and optical drives works outside the specification.

True, not everything adheres to the specification. 2.5" external hard disks in particular rely on ignoring it and hoping the host computer will be okay with immediately giving all the necessary current.

Anyway, I checked your links and they seem reasonable. It looks like consumption varies depending on brand and model, but overall, the numbers are around what I'd expect.