Hello everyone, Well my iMac has been quite slow for a few days. In fact since I've been installing an airport extreme with a usb disk and making my timemachine transfer on this disk, using it quite much besides. for the past day time machine has been backing up through ethernet. But I don't really know if the slow downs are due to RAM, CPU or HDD. I've set the activity monitor dock icon to show the CPU usage and it nearly never goes to 100% even during a slow down. That would leave us with RAM or HDD. I've attached a screenshot of the activity monitor which shows very little free RAM, although I've read this could be quite normal due to the Inactive RAM. My iMac software are up to date, here's what's runnig: Time machine backing up to ethernet firefox (5 tabs) thunderbird adium skype rss client spotify activity monitor Thanks!