I've only had my new Mac mini a few days, but I've noticed nearly constant hard disk activity, even when the machine is doing nothing. My office is nearly silent when I start work in the morning, and I was puzzled by the slight ticking from my computer. I opened Activity Monitor, and under Disk Activity it shows nearly constant activity under writes out/sec, data read/sec, and data written/sec. The amount of data is only about 4k to 500k, but it is constant, and I can hear the hard drive working when the computer is doing absolutely nothing. I have 16GB of RAM and a regular factory hard drive. It's not a problem and there are no performance issues, but I'm curious. Is this normal computer behaviour?