2 SOLIDWORKS Tips For Working with Large Assemblies

SOLIDWORKS Large assembliesDo you often find that your SOLIDWORKS large assemblies are sluggish? Do you experience slow open time, lag, and a slow save time? If you do, you’re not alone, but there are several variables you may not have considered that could be causing this lackluster performance. In this blog series I’ve been covering each of those variables to help you get your SOLIDWORKS large assemblies opened, working, and saving faster.

In my first blog, I showed several examples of a large assembly that was slow to open, slow to save, and slow to work with. We were able to remedy that by opening the assembly locally, we turned off shadows and shapes, real view, and changed the display to shaded. In part 2, I talked about network bottlenecks and the differences in hard drives and how those can affect how your large assembly performs. Part 3 introduced the “Automatically Load Components Lightweight” option in SOLIDWORKS and how to reduce the amount of data being opened. Continuing with that trend, today we’re going to talk about a couple of best practices for working with assemblies in general but especially with large assemblies.

As you’re working through these different tips and tricks, make sure you reference this checklist, which will help keep you on top of troubleshooting when working with your large assemblies.

Are all of your files saved in the current version of SOLIDWORKS?

The first best practice is making sure that all files are saved in the current version of SOLIDWORKS. If you have a file that was last saved in SOLIDWORKS 2016 and then your company upgrades to SOLIDWORKS 2017 when you open that file for the first time, it’s going to take a little bit longer to open than it normally does.

The reason why is because SOLIDWORKS actually upgrades the parasolid kernel (that is, the shape manager) that SOLIDWORKS is built on for every release. This means that when you go from SOLIDWORKS 2016 to SOLIDWORKS 2017 there’s a bit of a lag the first time you open your files. Once you open them, they are upconverted and when you save them they will be much faster to open the second time.

When it comes to assemblies, this issue is compounded, so if you have 100 parts in your assembly, then you’ll have to wait for 100 files to upconvert and then once you’ve saved that assembly and save all of those parts, the next time you open the assembly it opens much faster.

SOLIDWORKS PDM user? Listen up.

This is an especially important concept for SOLIDWORKS PDM users because if you have an assembly with 100 parts in it, you might only check out two or three of the parts, work on them, save, and then check back in. What this means, is that when you open the assembly, you have to wait for all 100 parts to upconvert, but you’re only actually saving those converted files that you’ve checked out, meaning you’re only saving, let’s say, three of the converted part files. Now you close the assembly and you open it again, and now you have to wait again for those other 97 parts to upconvert once again because they’re still in the older version of the software.

So if you’re a SOLIDWORKS PDM user, you’ll want to make sure that your PDM administrator recognizes this phenomenon and that they have a mechanism built into the upgrade process that will upconvert the entire vault.

Another option, is to enact a policy among the users where you say, “listen, when we get a new version of the software, make sure you check out the entire assembly and all of the parts” that way, when you open the entire assembly you are able to save and check in all of the parts in their upconverted state. This also means that the next user down the line won’t take the same lag.

Often time our SOLIDWORKS tech support team will hear SOLIDWORKS users say, “when we were working in SOLIDWORKS 2016 our assemblies opened much faster but now, no matter what computer we go to, the assemblies take much longer to open”. Well, the issue could be that you’re working in a PDM vault and you’re not actually upconverting the assemblies when you’re opening them for the first time because you’re not checking out all the part files.

So again, just make sure that when you’re working with assemblies or large assemblies in SOLIDWORKS, that you’re upconverting all of the files to the current version because it will make the assemblies much faster to open.

Check your SOLIDWORKS design for errors

The other best practice I have to share with you is to make sure all of your errors are resolved. You don’t want any errors in the assembly. These could be mate errors, mate errors in subassemblies, featured errors, or errors in imported geometry. If you have any errors in your assembly it’s going to create a wildcard scenario and it’s certainly going to cause the assembly to have more lag and require more processing power.

So a general best practice, when you’re working with large assemblies, is that there should be no errors, and this will ensure that you’re getting the best performance from SOLIDWORKS not only at the assembly level but at the drawing level.

Let’s take a look at an example of upconverting our assembly.

As you can see from the video above, by upconverting, we saved a significant amount of time. All we did was open the assembly and upconvert all the files the first time, save it, close it, and now from this point forward, whenever we open it, it’s  going to open faster because now all the files don’t have to go through that conversion process.

The next step I’ll take is to look through my assembly and dig down to see if there are any errors in the subassembly and parts and try to figure out where the error is and get those errors resolved because they could be causing unpredictable or abnormal behavior and it’s going to be much easier to troubleshoot and work with large assemblies when you’re not working with that wildcard.


If you’re newer to assembly management, you may not know that fewer top level mates will result in better assembly performance, which means you’ll want to effectively utilize subassemblies in SOLIDWORKS. When you have a subassembly, all of the mates that are related to those components solve at the subassembly level not at the top level assembly.

Basically, you’re better off having 10 subassemblies than having 300 loose parts. You’re better off taking those 300 loose parts and putting them together in subassemblies of 30 parts each and then ending up with 10 subassemblies because the mates between those components at the subassembly level will not solve at the top level.

That wraps up today’s tip on large assemblies and how to make them faster in SOLIDWORKS. In my next blog I’m going to talk about how to take your components and create simplified configurations, so stay tuned.

Related Articles

Large Assemblies and How to Make Them Faster (Part 1)

Help! My SOLIDWORKS Large Assembly is Slow to Open

Why You Should use the Automatically Load Components Lightweight Option in SOLIDWORKS

About the Author

Toby SchnaarToby Schnaars began using the SOLIDWORKS Software on the ’98 plus release, in October of 1998. He began working for Prism Engineering (now Fisher Unitech) as an instructor and tech support engineer in 2001. He has fielded over 10,000 tech support cases and been the head instructor for over 200 SOLIDWORKS training classes. Toby is a regular presenter at users groups, technical summits, and SOLIDWORKS world. In 2003, in Orlando, FL, Toby won first place in SOLIDWORKS MODEL MANIA a modeling contest based on speed and accuracy. Toby hosts a free monthly webinar called “Toby’s Tech Talk” where you can tune in and get more tips and tricks on the SOLIDWORKS software.

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