[megasad]

This article reminded of a foolish (but cheap!) USB 2.5" enclosure I have knocking about, that requires a Y splitting USB cable to get enough juice on my iBook and my ladyfriend's PowerBook.

If anyone has such an enclosure, could you check to see what happens when you plug it into either USB port on your MacBook?

In the comments for that article I linked to, someone says how their MacBook Pro has one port that does provide enough juice and one that doesn't.

Hopefully the MacBook will have at least one...

[ghporter]

A standard USB 2.0 port should power at least ONE 2.5" hard drive without any problem. I have a "USB to IDE adapter" that allows me to plug a 2.5" drive into a USB port; it works flawlessly with even older (and presumably more power hungry) laptop hard drives.

If there are more devices connected to the same controller, this might change the situation. But USB manages device power (unlike firewire), allowing or disallowing a device to turn on if the port cannot provide sufficient power-or more to the point, preventing an added device from overloading the port.

With that said, there are nonstandard USB solutions available that do a lot of goofy things. Some, for example, use poorly designed USB interfaces that draw a lot of power themselves. It sounds like that's what you have. My adapter is the Bytecc BT 200. The power supply is for 3.5" (and 5.25") drives. The down side is that it's not an "enclosure" so it's not a long-term solution, but this does show that not all USB drive solutions are clunky like the one you have.

[tooki]

A USB port is not required to provide more than 500mA (0.5A) of current. Nor can a USB device request more than that. Most laptop drives draw about 1A to spin up, so on any USB port that strictly enforces the 500mA ceiling, the drive will fail to spin up. This is why so many USB drives use two ports, to get each one's 500mA allotment and have enough power to spin.

tooki

[megasad]

I appreciate the information from you both, I do, but all I was hoping for was someone to see what happens when they plug one of these naughty drives into a MacBook.

As far as such drives being bad USB drives, using too much power; I know they are bad, but I have one already and so I'd like to know whether or not it will work sans wank-cable.

[ghporter]

Originally Posted by tooki

A USB port is not required to provide more than 500mA (0.5A) of current. Nor can a USB device request more than that. Most laptop drives draw about 1A to spin up, so on any USB port that strictly enforces the 500mA ceiling, the drive will fail to spin up. This is why so many USB drives use two ports, to get each one's 500mA allotment and have enough power to spin.

tooki

That's interesting. The three laptop drives I have onhand (and not installed) to play with are rated at 500, 520, and 700mA respectively. I guess the VIA chipset on my PC motherboard doesn't "strictly enforce" the USB standard.

As a laptop drive has no separate power connector, it's hard to apply a separate power source to it-a dual-plug adapter would not only have to connect to two different USB ports, but it must also isolate the different power feeds. Each USB channel has its own power allowance and a separate fuse, so just wiring them together won't work properly.

[GoDucks]

I may be able to help answer your question. I have a LaCie USB 2.0 "Rugged" Hard Driver that is supposed to draw power from my laptop. When I was using it with my 12 Inch Powerbook it did not draw enough power so I had to use the second USB drive. On my new MacBook however, the single USB cable is enough to power it up and transfer files with no problem at all. I guess different drives may be different but the MacBook does seem to allow you to draw more power from the USB ports than the 12 Inch Powerbook.

[megasad]

Originally Posted by GoDucks

I may be able to help answer your question. I have a LaCie USB 2.0 "Rugged" Hard Driver that is supposed to draw power from my laptop. When I was using it with my 12 Inch Powerbook it did not draw enough power so I had to use the second USB drive. On my new MacBook however, the single USB cable is enough to power it up and transfer files with no problem at all. I guess different drives may be different but the MacBook does seem to allow you to draw more power from the USB ports than the 12 Inch Powerbook.

Thanks for testing that. I've found the same too, with my own wank USB enclosure; I can use it with my MacBook using a simple USB to mini-USB cable that I got with my camera, no need for foolsh Y splitter at all.

The reason I was wondering about this was that when the 200GB 7200rpm SATA 2.5" drives come out next year, I'll want something to put my current 60GB drive inside of. Hopefully, by then, USB 2.0 sata 2.5" enclosures will exist and be as cheap as current IDE ones.

[Socially Awkward Solo]

OMG I love the title of this thread