Hi There I am running AutoCAD Civil 3D 2012 on my pc, but i'm constantly struggling with performance problems. From laging to not responding. I have got a rather strong pc...Intel Core i5 650 3.2GHz5GB DDR3-1333 RAM64-bit Windows 7 Pro Operating SystemGeforce GTX460 Graphics Card. So now my question is: What can be wrong that I keep on struggling with performance issues?? Thanks People

You might have a corrupted file.  Have you tried purging then running an audit on the drawing?

Well purging I know, but how do I audit a drawing? What will the audit help?

Audit finds and fixes errors.When you purge do you use the command line version of PURGE with the < - > (dash) in front of it making sure to first purge REGAPPS then rerun PURGE with the ALL option?You got to know and use all the tricks.

1.  Are you running the Aero theme in Win 7?  Don't.2.  Is Hardware Acceleration on or off in your C3D installation? Change it whatever setting you have and see what happens.3.  Is Selection Cycling on or off?  Off is best unless you really need it.4.  Have you gone thru everything in Options > System > Performance settings?  Checked for graphics card updates?  Looked at the Degradation order list?5.  Do you still have performance issues if you only run C3D?  Or are you running many other applications?These are a few things you should consider if you haven't already.Dave.

I think that PC specification is ok.Have you tried another versions for your PC? 2011 or 2010 version.

I would not recommend uninstalling 2012 and reverting to a previous release unless you had exhausted all your options.  Are you making use of xrefs?Is your scale listed bloated?Do you use layer filters?Have you killed the CommCenter?Is this problem with just one drawing or all drawings?What is a typical file size?If you are doing all your work in 3D maybe you need to boost the amount of installed RAM?