100hz/1080p output with HDMI

[scott_mckenzie]

Hi,

I've got a new LG tv - 42LG70YD which can do 1080p at 100hz.

My upgraded VMC box has the ASUS M3A78-EMH HDMI motherboard. When I set my graphics to 1920x1080 outputting through HDMI, my TV identifies the HDMI @ 60hz.

When I look at my mobo specs, it doesn't state the refresh rate over HDMI, however it has the following:
- Supports DVI-D with max. resolution 2560 x 1600 (@60Hz Dual-link)
- Supports RGB with max. resolution 2048 x 1536 (@85Hz Dual-link)

I guess what I don't understand here is if I can simply output 100Hz via HDMI with 1920x1080. When I try to configure it I can only see a maximum of 60Hz in the Catalyst settings but am not sure if there is a way to get 100Hz or not.

Any suggestions would be greatly appreciated.

Cheers - Scott

[Lester_Burnham]

Hi,

I'd try setting it to 50Hz, as the TV may double the refresh rate itself.

Lester

[TheRob]

Originally Posted by scott_mckenzie

I guess what I don't understand here is if I can simply output 100Hz via HDMI with 1920x1080. When I try to configure it I can only see a maximum of 60Hz in the Catalyst settings but am not sure if there is a way to get 100Hz or not.

With a HDMI connection the drivers should show you the resolutions the TV tells it that it can support, and that your GPU can also support. As the post above says, you should set it to 50Hz and let the screen worry about doing the refresh. You won't have any material that will be recorded at a 100Hz frame rate, so it shouldn't make any difference anyway.

[merovingian]

Just to be clear, 100Hz TVs don't accept a 100Hz input. Instead they interpolate intermediate frames to effectively double a 50Hz input to 100Hz (as Lester suspected, but he wasn't sure). So you want 50Hz output from your graphics card.