My 2007 iMac is extremely slow, yet memory and CPU are not starved

Question

2007 iMac, 2 gigs ram, internal 320G hard drive.

Even after a reboot and clearing some log files locations, the computer is very slow. Programs start up slowly, opening new terminal windows is very slow (over a minute to get a prompt), starting up a new MacVim window (MacVim already running) takes over a minute. Don't even get me started on iTunes and iPhoto.

It wasn't always like this, and I'm wondering if I have hard-drive fragmentation or some other issue with the drive. I have done the "repair permissions" and "repair disk" and it seemed to help for a few days, but then was very slow soon after.

The drive is consistently filled, with somewhere between 5 and < 1 gigs free. I have both Time Machine and Backblaze set up, but when both are idle, they consume near-zero CPU and very little memory and the machine is still pretty slow.

So, I can think of three options and wondering if there are others and what might the effectiveness of these options.

1. Do some sort of "defrag" or re-imaging of the current drive
2. Swap it out for a bigger one (perhaps the starved disk space is making other things fight for space)
3. Swap it out for a similar or smaller sized SSD

Any other ideas?

Answer 1

Lack of hard drive space is likely a concern. Regarding your listed options:

1) is not likely to make much of a difference by itself, unless your hard drive is failing or there's software corruption. If you're getting SMART errors, your should be alerted to that fact and it would show up as red in Disk Utility.

2) if the free space is the issue, which seems most likely, this would solve it. But make sure the bigger drive is as fast or faster than the currently installed one.

3) this would get you the most speed benefit, but with the added complexity of having most of your files on the external hard drive. You sound like you know what you're doing though, so this probably isn't much of an issue. I wouldn't recommend this to my mother, but you'd be fine doing this.

Some other things you could try is move off about 10GB onto a flash drive, or just delete them and you can restore from Backblaze. Then, if it's still not faster, try creating a new user, log in as the new user and see if it's still slow.