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External Enclosure + Adv Format - power draw & allocation unit size?

February 27, 2013 7:40:02 PM

3 questions about external enclosure & advanced format drives:

I just got a 750 GB WD Black 2.5" (mobile) -WD7500BPKT- and I want to use it in this external USB3 enclosure - I'm wondering if I can use a standard USB3 cable, or if additional power is needed. The enclosure comes with a "Y-cable", which is double-USB to a mini-USB.

The enclosure has a note: "CAUTION!! When using USB 3.0 interface mode, external power is needed when HDD consumes power over 900mA".

The HD's spec sheet lists a "5VDC ±10% (A, peak)" of 1.15.
WD7500BPKT specs:

Is this the power spec I'm looking for? Does this mean it draws 1150mA, exceeding the capabilities of a single USB3 cable? If so, can I use the included Y-cable, or must I get the power supply accessory from the maker of the enclosure?

> Question 2: This is an Advanced Format drive ( I'm wondering if I need to run the special alignment software, for compatibility between machines (will be using with clients). For example, if I format it on my Win 7 machine (AF-ready), will it be usable on a client's Win XP machine?

> Question 3: Will alternative allocation unit sizes work with an AF drive, or must I stick to 4096? I believe there is a difference between sector & cluster size, & I'm not sure whether this is even relevant. I personally will stick with 4096 for now, but I sometimes assist folks with workstation setups, who might be interested in a larger allocation unit size.