I know this is a very old question.. I recently had the same problem of jagged lines.. I resolved this problem by going to 3dconfig in autocad command promt. In the dialog box ( adaptive degradation and performance tuning ) select manual tune and change the settings..
smooth display from off to on
if unchecked , select smooth faces by default
change dynamic tessellations - curves - push slider to high detail more memory
Hope this suggestion helps others who are facing the same problem.
Changing the resolution of the monitor was not an option since it was already in the highest resolution possible for the monitor. A few specs in case it helps others - my monitor is a led monitor . The software is Autocad 2012 and I have hardware acceleration enabled.
You say it is an LED monitor
What is the connection to the CPU?
Analog or Digital?
And if Digital is it HDMI or DVI?
And is the graphics card in the CPU the same?
Sorry for not replying earlier.. I didn't have email intimation enabled.. I am not too familiar with the hardware side but from what I could figure out (visually/graphics card specs) the connection is DVI in both led monitor and the graphics card .The graphics card is from nvidia. I was trying for quite a few days to find a solution to the problem of jagged lines and this above mentioned method helped me out.I mentioned the hardware specs in case that had some connection to the problem.
The resolution could be at its highest but not necessarily the native resolution.
Have you tried other resolutions to see if this goes away?
Resolutions are not linear. Most see a problem with circles being ovals with a non-native resolution.
I did try other resolutions but it had no effect. The native resoultion is the highest one in my monitor which was my default setting. My problem was just like zoid described above. The horizontal lines were straight, but any angular lines would have jagged effect. After changing the 3d config settings the angular lines now appear smooth and I have not experienced any other problems. May be it had something to do with anti-alias which was corrected by changing the smooth settings. Not being a technical person,I cannot confirm it is linked to anti-alias.