DMIDecode to find used RAM slots

So, someone asked if there was a way to find out which memory slots were used in a running machine without opening it using Linux. Here’s the answer:

$ sudo dmidecode | grep "Installed Size"
        Installed Size: 1024 MB (Double-bank Connection)
        Installed Size: Not Installed
        Installed Size: 1024 MB (Double-bank Connection)
        Installed Size: Not Installed
        Installed Size: 64 KB
        Installed Size: 2048 KB

If you just run sudo dmidecode by itself, you can find out all kinds of awesome system info.