I have ATI Sapphire 5870 1GB DDR5 and i bought new Screen
LG Cinema 3D 32LM5800 32 inch 3D LED LCD HDTV http://www.lg.com/us/tvs/lg-32LM5800-led-tv
This Screen support up to 120Hz but no more then 60 Hz in both Catalyst or Windows Settings !!
My Driver is updated with the latest version 12.4
Plus i'm using BELKIN F5Z0312cw HDMI Cable
PLEASE HELP !
120Hz HDTVs 120Hz PC monitors operate differently. They follow different design standards.
120Hz PC monitors accepts 120Hz inputs either through dual-link DVI or HDMI 1.4a connections. As long as the graphic card can send 120 frames per second to the monitor the monitor will display 120 FPS.
120Hz HDTVs only have 60Hz inputs. However, the output is at 120Hz. Basically the HDTV creates an interpolated frame in between each actual frame; so 60 frames in, 120 frames out. This helps make movies playback smoother because movies are filmed at 24 frames per second. A HDTV with the post processing turned off (i.e. 60Hz mode), the HDTV will display 60 frames per second. Since 24 does not divide evenly into 60 that means some frames are repeat which causes movies to sometimes stutter.
When a HDTV is in 120Hz mode, it processes the incoming frames so that there are 120 frames per second. Since 24 divides evenly into 120 (by 5) movie playback is smooth because no frames are repeat every second. This is great for movies, but bad for games since the video post processing takes time. This means it causes input lag. Therefore, when playing games on any 120Hz HDTV it's always best to set it to 60Hz mode.
Just a note, but HDMI 1.4a does not support 120hz for normal use. To get 120hz, frame packing is required, and as far as I'm aware, frame packing is only used for HD3D. I have an HDMI 1.4a monitor and it also cannot be set to 120hz through HDMI, but on AMD cards, it can use HD3D at 60hz per eye (effectively 120hz), though only at 720p (I didn't try 120hz at 720p, it may be possible for 120hz at 720p...I still believe it is not listed in the specs).