In honor of Gentoo's 10th birthday, we are producing a new livedvd! We need YOU to test it on as many x86 and x86_64 machines as you can and post bugs. Please report your bugs. Feel free to entertain yourself and fellow Gentoo rock stars on our forum.
The livedvd-x86-x86_64 will work on x86 or x86_64. If your arch is x86 boot with the default gentoo. If your arch is amd64 boot with gentoo64. The livedvd-amd64 is for well, amd64 only.
rest here