Sleep function on iMacs ?

[dwighty pork]

I have an iMac 24 from 2009 and an iMac 27 from early 2011 with i5, both running O.S.10.6.8 as I have zero wish to use Lion now or in the future...
The 24 has the 640 gb hard disk and the 27 the 1TB.
I usually put the machines into sleep mode at night but have been surprised to find that whereas the 24 remains stone cold while in sleep that the 27 can run quite warm in the same function.
Checking the Activity Monitor on the 27 after awakening from sleep,I see that the CPU is busy - I do have a large iTunes library with many films I watch via Apple TV, and I note that Quick Time takes up most of my usage, presumably down to this ?
Is it better to close down applications like iTunes, Vuze, Skype and Firefox before I put the machine into sleep mode - and also to keep your iTunes Library small and just store movies on an external hard drive (as I do anyway..) and load them when you intend to watch ?
Any thoughts welcomed.

 

[GGJstudios]

I usually put the machines into sleep mode at night but have been surprised to find that whereas the 24 remains stone cold while in sleep that the 27 can run quite warm in the same function.

It's possible that it's not staying in sleep mode. If that's the case, you may find some useful ideas here:

Mac OS X: Why your Mac might not sleep or stay in sleep mode
Determine why your Mac wakes up from sleep
One sleep problem caused by printers - solved ... and another

Checking the Activity Monitor on the 27 after awakening from sleep,I see that the CPU is busy - I do have a large iTunes library with many films I watch via Apple TV, and I note that Quick Time takes up most of my usage, presumably down to this ?

What processes show to be using CPU resources? Launch Activity Monitor and change "My Processes" at the top to "All Processes", then click on the CPU column heading once or twice, so the arrow points downward (highest values on top). Also, click on the System Memory tab at the bottom. Then take a screen shot, scroll down to see the rest of the list, take another screen shot and post them.

Is it better to close down applications like iTunes, Vuze, Skype and Firefox before I put the machine into sleep mode

There's no need to close anything before sleeping, unless you have some app that's preventing sleep.

and also to keep your iTunes Library small and just store movies on an external hard drive (as I do anyway..) and load them when you intend to watch ?

There is no need to restrict the size of your iTunes library. As long as you have sufficient disk space, it's fine. If you run out of space on your internal drive, you can split your library between internal and external drives.

How to split a single iTunes library over two or more media locations