How much power is required for a SuperDrive?

I don't mean from rumor sites, actual figures please, either from Apple or a representative testing agency (such UL) or some other. MacRumors is called that for a reason.

djcastaldo wrote:

Ok, well it seems you think that if the OP goes out and exchanges his superdrive for a different one that his current hubs will suddenly start working. I am simply stating that I don't think so, I think that Apple designed the drive outside of USB spec.

Here is a link from Apple stating that Apple designs some USB devices that require more power than the USB spec: http://support.apple.com/kb/HT4049

Nice link, next time read it.

It says that these Appe devices may request more than 0.5a under some conditons.

• Apple MacBook Air SuperDrive (when connected to supported computers)
• Aluminum Wired Keyboard*
• iPod
• iPhone
• iPad

To meet requests for additional power from these Apple peripherals and devices, some Apple computers and displays can provide up to 1100 mA at 5 V through the port to which the Apple peripheral or device is connected. This power is available under certain conditions:

1. An Apple peripheral device must be plugged directly into an Apple computer or display. Apple peripheral devices connected to hubs will not have access to extra power above the standard USB specification of the port the device is connecting to (500 mA for USB 1.1 or 2, 900 mA for USB 3).
2. Your Apple computer or display must be powered on and must be awake. If your Apple computer or display is asleep, all ports will provide their normal maximum output. If your Apple computer or display is powered off, no power will be provided.
3. The port providing extra power is determined by the first Apple peripheral or device to connect to the Apple computer or display that requires power beyond 500 mA for USB 1.1 or 2, or 900 mA for USB 3. The remaining ports will continue to offer their normal maximum output. Some Apple computer and displays may offer the ability to operate more than one USB port at 1100 mA at 5 V. On those computers, the second or third port is enabled when an appropriate device is connected.

The devices that provide the extra power exclude:

Apple computers and displays that were introduced before 2007 support only 500 mA at 5 V from their ports and do not offer additional power.

Why choose to ignore that?

Roger Barre wrote:

It's hardly "nonsense". here a quote from Apple's own Knowledge Base:

"Apple peripheral devices may request more than 500 mA (Milliamps) at 5 V (Volts) from a port to function or to allow for faster charging. Such Apple peripheral devices include:

Apple MacBook Air SuperDrive (when connected to supported computers)"

See above. and please stop quoting only the part that you prefer, we are not stupid.

I don't understand the argument anymore. The quoted part that you put in bold clearly shows that 1100mA is needed for some Apple USB devices to function.

EDIT: to the OP: there are some USB hubs that can supply higher amperage to facilitate faster device charging. If you get one of these hubs, you could probably get your superdrive to work.

djcastaldo wrote:

I don't understand the argument anymore. The quoted part that you put in bold clearly shows that 1100mA is needed for some Apple USB devices to function.

And that Apple computers and displays since 2007 will supply that. Furthermore IT IS PART OF THE USB SPECIFICATION, which you keep on ignoring. Nothing is new here, except your miscomprehension!!!!!

Roger Barre wrote:

There is nothing wrong with the SuperDrive.

Correct.

Apple Cinema Displays were introduced in 1999. OP didn't say his display was new.

Here's some numbers for ou

Superdrive:

Initial inrush: 0.45a

Quiescent; 0.25a

Spin up: 0.88a

Read: 0.45a

Write: 0.65a

Test conditions. Tektronix bench supply (5vdc) Fluke current clamp.

That's what I got last time I tested one, no guesses.

It is fully compliant with USB2 specifications, if there is insufficient power for it to run then it, or the supply, is out of spec and should be attended to.

Me, I'd return it to the store.

I use my Superdrive with a Belkin hub, the USB ports on an HP Monitor and various MBP's, I can not replicate your issue, sorry. I don't have a Cinema display but I have had various hubs that worked without problems, but I guess you can plug it into the Mac for now.

It is a F4U041v, 7 ports, USB2

I can confirm the issues with USB hubs and Apple's (non-Thunderbolt) Cinema displays. My superdrive also doesn't work on anything else than my MacBook Pro's USB port.

Googling on this matter, I found this:

http://www.tuaw.com/2008/06/24/mod-use-your-macbook-air-superdrive-on-any-machin e/#comments

From this, I read that Apple intentionally used a modified firmware on the USB-to-IDE adapter in the superdrive to prevent the superdrive from working on anything other than their notebooks. As Csound1 stated above, it's not an issue with power consumption.

The only way to get the superdrive working on USB hubs (or on other non-Apple computers) is to replace the internal USB-to-IDE adapter (which has been successfully done already, see the link above)...