ATI drivers using too much RAM and CPU

Possibly Catalyst files corrupted. Try to reinstall it.

What you (really) need to use the ATI Catalyst drivers is the service AMD External Events Utility started in automatic mode.

Catalyst® Control Center Launcher or CCC.exe is as far as I know useless and can be disabled (with Sysinternal's Autoruns for example). You don't have to run this utility at each boot...

The ATI drivers (amdkmdag.sys and atikmpag.sys) are loaded at system startup with or without CCC

It still possible to start Catalyst Control Center manually ("C:\Program Files (x86)\ATI Technologies\ATI.ACE\Core-Static\CCC.exe"). CCC is also used for automatic drivers update but please note that AMD montly update policy has been changed:

Extreme Tech: AMD rethinks driver strategy for graphics, halts monthly updates