I use 8 gigs in mine under windows 7 x64. Make sure you are using an x64 version of the OS if you plan on 8. Will work fine on both Windows 7 & 10 & Linux distros as long as you are using a compatible x64 version of it. I prefer Windows 7 because of the ability to hack and modify the boot up and shutdown screens, turn off updates so you can administer remotely and have it connected to wi-fi. I also prefer older boards like the socket 1155 or 1150 that are name brand like Asus, MSI and have BIOS boot logos that can be modified. You don't have to do all that at all, you can easily use an old Dell or HP board with Windows 10 and hide the OS and boot right into your front end, but I like customizing personally.