Choosing the right connector is important.

USB2 is slow, but cheap and highly compatible. Just about everything that reads data from a drive will support USB2.

USB3 is the fastest [provided you have a USB3 port on your PC or laptop], not so cheap, and highly compatible. It's fully backwards compatible with all USB2 [and I'd assume USB1] devices. It will slow itself down to USB2 speeds when talking to USB2 devices.

Firewire is fast, not so cheap, and there aren't many devices outside of Apple and Sony which support it. Use it if you know that every device you'll want to connect to also supports Firewire. Some non-Apple/Sony PCs do have firewire ports, but they're not commonplace.

eSATA is very fast, I don't know what price [should be quite cheap, it's a standard SATA 300 port with a funny shaped connector to prevent mis-use], but has even worse support than Firewire. Only bother with this if your portable hdd is going to stay anchored to a machine with an eSATA port. Performance PC's from the past several years are likely to have eSATA.

The relative speeds are:

Code:

USB 2.0        [60 MB/s]
FireWire 800  [100 MB/s]
FireWire 1600 [200 MB/s]
eSATA         [300 MB/s]
FireWire 3200 [390 MB/s]
USB 3.0       [625 MB/s]

I have drives with all of those, except for USB 3.0. Personally, I find USB 2.0 to be the most useful due to its widespread popularity. I can take a drive anywhere and know that it will always work. It can stream 1080p movies directly off the drive without a hiccup. If you need a very high transfer speed for uncompressed video editing or the like, then USB2 is not suitable.

 

I wonder how much a Petabyte drive would be.

Endless porn.

 

Don't you have internet for that?



/challenge accepted

 

I don't think that there are many HDD's with read/write more then 60 mb/sec so connector should never be a problem (HDD that fast are really expensive, and the always have the right connector). USB 2.0 should be enough for any HDD.

 

No. Just, no. "USB 2.0 should be enough for any HDD." LOL. You've reminded me of that often attributed to Bill Gates quote "640kb ought to be enough for anybody."

The speeds I quoted were the theoretical maximum transfer rates, not the actual sustained transfer rates in the real world with data overheads, disk and file structure, etc. They were quoted for comparison of the interfaces speeds with one another. It gives a good picture of their relative positions and the gaps between them. I'd have posted real world speeds, but the theoretical maximums were all I had.

Of USB 2.0's theoretical 60 MB/s, in the real world you're only going to see about half of that, around 30 MB/s. With 2.5in portable drives now sitting comfortably in the 50MB/s to 95MB/s [really pushing at 100MB/s] in real world transfer tests, USB 2.0 has been completely hosed for years.

Internal, fully powered 2.5in and 3.5in hard disks are way past 100MB/s in real world testing.

http://www.techarp.com/showarticle.aspx?artno=511&pgno=4
http://www.notebookreview.com/default.asp?newsID=6059&p=2
http://en.wikipedia.org/wiki/Universal_Serial_Bus#Transfer_speeds_in_practice
http://www.everythingusb.com/usb2/faq.htm#4
http://www.laptopmag.com/reviews/storage/iomega-usb-3-eGo.aspx

 

Sorry, we live in different countries, so maybe what you say is true, but I think you just misunderstood me. What I am trying to say is that you shouldn't look at the connector of external HDD and that numbers that yak wrote, you should look at disk read/write/access etc. speed instead. I never saw a fast HDD with a slow connector but I saw lots of HDD with, for example, FireWire that had read/write less then 40 mb/sec. And USB 2.0 should be enough for any common disk usage: films/music etc. And I am talking about what "Hero of Stupidity" was asking for: 2.5-Inch about 512Gb USB-powered for about 70$.