Mac Pro with TV LCD?

If the TV does not have a DVI port, you usually need an adpter to HDMI.

Not only will you have to adjust Mac settings, but you are very likely to have to adjust TV settings as well.

Remember: A TV set is not a monitor. You will not get crisp text and clear sharp lines whatever you do. That requires a monitor.

Set to 1080p or 1080i, you may have to adjust underscan or overscan to properly fill the screen.