https://bugs.freedesktop.org/show_bug.cgi?id=26195

--- Comment #25 from Alex Deucher agd5f@yahoo.com 2010-04-13 12:59:08 PDT --- (In reply to comment #24)

However now I get overscan on the HDMI where I had 1:1 pixels before.

Did you change any settings on your TV? Some TV's overscan by default unless you disable it in the TV options.