iMac G5 running so slow

[eyemacg5]

Today my iMac has been running so slow. I can type a whole sentence before it will appar on my screen. I'm using Firefox, pages, adium and itunes. In firefox the lag is awful between clicking different tabs and it actually switching, this is the same in safari and opera. With pages it takes 5 minutes for me choosing to highlight something and it actualuly doing it.

iStat is saying I have 100% CPU Usage Using 900mb of my 1.5gb ram

Temperatures are
CPU 74 ºC / 165 ºF
GPU 65 ºC / 149 ºF
Incoming Air 20 ºC / 68ºF
HD Temp 43 ºC/ 109 ºF
GPU Ambient 27 ºC / 80 ºF

Its a last rev iMac G5 w/ iSight 2.1ghz 1.5gb ram 20"

Edit: Its beachballing nearly all the time

 

[Blue Velvet]

How much spare space is free on your hard drive?

 

[eyemacg5]

102.48gb

 

[Blue Velvet]

How quickly does the Mac start up? Have you tried rebooting? Have you run Disk Utility over the drive as a preliminary check?

I'm not saying that this is the likely problem, but this sounds identical to what happened to my friend's iMac before the drive failed completely. No clicking and no other obvious signs of failure... Fortunately, all her work was backed up on a daily basis.

 

[eyemacg5]

How quickly does the Mac start up? Have you tried rebooting? Have you run Disk Utility over the drive as a preliminary check?

I'm not saying that this is the likely problem, but this sounds identical to what happened to my friend's iMac before the drive failed completely. No clicking and no other obvious signs of failure... Fortunately, all her work was backed up on a daily basis.

Ive repaired permissions and tryed to verify disk and I get this

Verifying volume “”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking multi-linked files.
Checking Catalog hierarchy.
%)
Checking Extended Attributes file.
Checking volume bitmap.
Checking volume information.
Volume Header needs minor repair
The volume  needs to be repaired.

Error: The underlying task reported failure on exit


1 HFS volume checked
Volume needs repair

Boot takes about 1 minute but It rarely gets turned off. uptimes is at 6 days 20hours

 

[skunk]

Ive repaired permissions and tryed to verify disk and I get this


Boot takes about 1 minute but It rarely gets turned off. uptimes is at 6 days 20hours

You'd be best off restarting the Mac from the OS DVD, and running Disk Utility from the DVD. Disk Utility will fix things much more effectively if it's not running on your Start-up disk.

 

[mkrishnan]

You'd be best off restarting the Mac from the OS DVD, and running Disk Utility from the DVD. Disk Utility will fix things much more effectively if it's not running on your Start-up disk.

However, be careful about this: you MUST do the Repair Disk item from Disk Utility off a boot DVD (this is what you need, based on the text you posted). You should NOT repair permissions using the boot DVD, as I understand it, because it does not take into account receipt files and modifications on your system beyond the version that was on the install disc, and could therefore repair permissions to the wrong state or skip files.