I guess this is a hardware issue and not software.Although could be a driver issue.
Anyway, I have my PC hooked up to my 42" HDTV through HDMI.This a problem both in Windows 7 ann XP and in Linux.It automatically underscans 15% and that leaves about a 1 inch border around screen.It does with HDMI and VGA.
In windows AMD driver has settings to adjust over/under scan. I just have to slide it back to 0% and everything is fine.
In Linux drivers there is no over scan option to correct this.Only thing I can do to fix this in AMD control panel is turn on scaling and have GPU scale image to fit screen.
Id there some way in Linux to correct this.A xorg.conf entry or something so I dont have to have GPU scale resolution up?
Like I said wasnt sure If this was more a hardware or software section question.
EDIT..WEll got it fixed after a bit of research. Ued aticonfig to fix it. Entered this in command line
# aticonfig --set-pcs-val=MCIL,DigitalHDTVDefaultUnderscan,0
Didnt work at first after rebooting but rebooted and logged in recovery mode and entered it.That did it.