Ok, since this thread is about hard disk, I would like to share some knowledge which many of you might know already.
1. Check your computer/notebook and see if you have eSATA port. It looks like this:
http://www.techchee.com/wp-content/u...er-449x339.jpg
2. eSATA supports 3Gbps data speed which is much higher than USB 2.0s 480 Mbps (both value theoretical)
3. Unlike USB 2.0 earlier eSATA used to come without power support. That means you need external supply for your external drive
4. New eSATA ports come with 4 small holes on the front side which are nothing but power supply. That means now new eSATA has power of old eSATA and USB 2.0
New eSATA is also known as "eSATA / USB Combo Port" or powered eSATA" or eSATAp or "Bus-powered eSATA"
5. Build your solution using eSATA now.
A) 2.5" SATA internal Hard disk + SATA to eSATAp cable
B) 2.5" SATA internal Hard disk + enclosure (with eSATAp port on it) + eSATAp to eSATAp cable
Manufacturer knows the pain point. As I write a mail, I am reading news below. They have come up with solution B but at premium. Low cost enclosure are available in market ($20-$35)
LaCie debuts bus-powered eSATA external hard drive | Crave - CNET
http://news.cnet.com/8301-17938_105-10452378-1.html
C) 2.5" SATA internal Hard disk + enclosure ( with old eSATA port + USB 2.0 port) + eSATA to eSATAp/eSATA cable + USB 2.0 Y or normal USB to USB cable for power and also external power AC adapter
Note : use either USB 2.0 cable to power up or external AC power adapter. In case of external AC power adapter, now drive is not mobile
D) 3.5" SATA internal Hard disk - not much idea but I believe eSATAps 5V DC is not enough for that. I think it requires 12V DC. External AC Adapter is must. That means drive is not mobile. However, please work out on eSATAp + USB 2.0 combination to power up the drive and check if works or rely on the manufacturer's recommendation as they might have implemented less power consuming models.
All this to get much better speed than USB 2.0
Now, we have USB 3.0 coming in the market this year, infect WDC and Seagate are already out. USB 3.0 supports 6 Gbps but you need to upgrade your machine with extra kit to get desired speed.