How Can Improve Surface Performance?

[gpserra]

Civil 3D surfaces mostly built with a corridor and some feature lines are typically good enough for projects that are under 10 Acres, but every time I start to pass the 20 and 30 acres mark I get 20MB files that can take up to 5 minutes to update some feature lines. Take the attached drawing for example. Some of the feature lines can be updated immediately, some take about 10 seconds and some will take more than 5 minutes. I know it's not the cleanest drawing, but this beast was never meant to be this refined. I've had to attached more and more feature lines because this local municipality has ridiculous expectations, requesting an excessive amount grading labels. 

I know I have a bunch of duplicate points, but I don't understand how. And if I use findsiteoverlaps to delete all overlapping feature lines, I just end up deleting the only feature line present and it ruins the surface. I was trying to just get by and just get it done, but it looks more and more like I have to rebuild this thing. I'd just like to know how to do it properly before doing it. The one thing I will try to do today, is to remove my corridor surfaces and reference them back in. Not sure that's going to do much, as I feel like the main issue is with the feature lines themselves. 

[chriscowgill7373]

What version of Civil 3D are you using?  Using 2025 or 2026 will give you a big improvement if you are currently on an older version.  There was a lot of work done to performance for surfaces in the newer versions.

Reducing edits in surfaces would help.  Dont combine surface types, if you are pasting surfaces, just paste surfaces, if you are adding breaklines, just add breaklines.  I've been doing this for a long time, and I cant say that I have ever seen anyone do edits to a corridor surface.   If your corridor is designed properly, you wont need edits.

Are some of your feature lines tied to grading objects, or used as base lines for corridors, that can cause edits to take longer, because everything tied to it needs to rebuild.  If you have a feature line tied to a surface and the corridor targets that surface, the corridor is going to have to rebuild when that feature line is edited.

[igi_pop]

Hey!

This looks like a PCB 😄

Jokes aside, I've opened it, rebuilt in a snap, all works well 🤷‍♂️

Working in '26 here.

Hope you find what's the holdup, and pick up on advice here @chriscowgill7373 , if applicable.

Iggy

[gpserra]

I'll try 27 and see if that makes a difference. 

[gpserra]

I've not switched to 26 yet, I like to skip a year and usually work on the odds. Not sure if 2027 is stable yet, but I'll give it a try. 

Not sure why I wouldn't combine surfaces. I've always pasted my corridor surfaces into my work surface where I also paste my feature lines. But as I said, this job got particularly dirty because this level of detail was never meant to be the goal, and I took the easy way out one too many times. As far as the corridor being designed properly, the only weird thing I did (again to save time) was targeting a feature line when I wanted the intersecting road to end at the gutter line. Other than that, it's all pretty standard, but the corridors frequently go out of date without me even getting close to them, so you may have a point. 

There's a feature line tied to the outer edge of the corridor that auto updates with the corridor rebuilds, but that feature line is not pasted in the work surface. It's just there at a higher hierarchy so that any of my drives auto updated when I was tinkering with road slopes.