OSX external HDD problem.

Factual Questions
1

So I bought an external HDD about a year ago. 320 GB job. It seems to do well, and I like it. But I’ve been having some problems with it lately, and I’m getting worried. It is connected to my iMac (the first intel type) via USB cable. Now I’ve had it in various roles, so I’m curious as to what’s going on here.

I first had it in use as my external back up disk when Leopard came out. All was good until one day, I couldn’t use it anymore. So I had to use Disk Warrior to rebuild everything and it started working fine again. I suspected that Time Machine was responsible for mucking things up, so I decided to stop the timemacine backups.

Also, it occasionally becomes unrecognized by the iMac. A quick unplug-replug cycle fixes that.

Now it has happened twice since with no Time Machine being active. After the second time, I went through and performed a surface scan to find no errors. So I thought I was in the clear. Now I ran into the problem once again. The only thing I can suspect it with would be Bittorrent. Of late, some of my downloaded files have been sitting around after finishing uploading. All of a sudden I get a message that they have been corrupted and are being redownloaded. I think this is probably an error with my bittorrent client, right?

So do I need to replace it? Or is it simply a question of getting rid of Azureus? I have another enclosure if that might solve things.

Anyone have any experience with such things? I’ve recovered it the other day and my stuff seems fine (although my files got mixed around). What say you, dopers?

2

I’d suspect a hardware problem with the hard disk or the USB bridge in the external enclosure. When I’ve seen problems like that, it usually means the disk is dieing.

3

My first suspect would be the USB connection, actually. Could be the connector at either end or the cable itself.

4

First of all, USB sucks for external drive usage. You would be better off with a FireWire drive. I’d make sure that the drive firmware is up-to-date.

5

Really? In what way? I’ve had both USB and Firewire HDs, and could tell little difference between them.

6

For casual use, USB is fine (I use it myself, sometimes). When you start doing heavy use, it’s performance is significantly worse than FireWire: http://www.qimaging.com/support/downloads/documents/FirewireUSB.pdf

7

Sure, but both of them are significantly slower than SATA and other interfaces. I wouldn’t use either of them where I/O performance was critical. And where its not critical, I can’t see someone easily noticing the difference between that paper’s mark of 33 v 38Mb/s.

8

You’re looking at the official spec / marketing bullshit table detailing what each interface is supposed to be able to do. Look at the benchmark box above (Fig 3) and you see that in actual use they claim speed differences of between 16%-70% depending on the scenario.
That sort of difference would be quite noticeable if it’s real.