The Only Two Tips You Need for SOLIDWORKS Assemblies

When SOLIDWORKS Assemblies get bigger, the stakes get higher—every click matters, sluggish seconds gets amplified and your system can come to a screeching halt. We all know the helpless feeling of the system locking up like brakes on a highway, bringing your productivity to an instant and incredibly inconvenient stop.

It doesn’t have to be this way. All it takes is a little insight into Large Assemblies and some tips on using the right tools. Let this article serve as the definitive guide to working with large assemblies in SOLIDWORKS 2021—including the only two tips you need to know.

What are Large Assemblies?

We’ll begin by defining a large assembly. It’s much more than a number; it’s more like how it makes you feel. (Bear with me. I know that sounds absurd, but it’s true.)

Allow me to explain. A “large assembly” could mean many different things to different people depending on the industry or even your own computer hardware. So, when you say to me, “But sir, I am an engineer. I rely on numbers and data. How can a large assembly be defined as a feeling?” I say to you, first, good question. You must remember the dread building up inside knowing you’re about to open that one model that takes an eternity to open. You must think of that all-too-familiar feeling of anxiety before a rebuild. You must not forget the lag that happens each move you make when you try to rotate your model. You must think of the times you could only stand by and watch your top-of-the-line computer be brought to its knees.

Those feelings are the price of admission with large assemblies. But that’s ok, because there are things you can do to help minimize these feelings and maximize your large assembly performance.

Tip 1: Update – Every. Single. Year.

This is a performance improvement built on a foundation of the code itself—as fundamental as it gets. When it comes to tips for working with large assemblies, this is the easiest and most straightforward of them all.

The first step to take to maximize your large assembly performance is to update your SOLIDWORKS software. I cannot understate how important it is to be using the most current version of SOLIDWORKS. With every major release, SOLIDWORKS spends a big chunk of resources on performance improvements which have a direct impact on large assemblies, or flashy new buttons and slick new features. Rather, the updated release just contains improved code that amounts to huge time savings.

Take a look at the image below which categorizes the enhancements to the latest release. For SOLIDWORKS 2021, more than 50 percent of the improvements were to improved quality and performance, while less than 25 percent were to enhancements. This sort of break down has been a common theme throughout the decades of SOLIDWORKS major releases. The latest release of SOLIDWORKS 2021 has some incredible time savings improvements that you unlock by just installing the latest version.

One example of how these improvements manifest themselves in an update is that the heavy lifting of performance (graphics) is improved so that the GPU is doing more of the heavy lifting instead of the CPU. This amounts to a quicker, more responsive and snappier experience when using SOLIDWORKS. Ask yourself, do you want better performance? The first, and arguably best step you could take is to update to the latest version.

Tip 2: Take Advantage of Assembly Modes

Assembly modes are tools built into the software which can help improve performance of large assemblies. When opening a large assembly, be sure to choose the best mode for the job. Think of this like drive modes in a car: you have the daily drive mode, but depending on the task at hand you’ll need to take advantage of different modes.

The different SOLIDWORKS Modes are Resolved, Lightweight or Large Design Review (LDR). These different modes will load different data from the SOLIDWORKS file. Before we go into detail about the Assembly modes, however, let’s first talk about the data in a SOLIDWORKS file. With an understanding of the functionality of a SOLIDWORKS file behind the scenes, it’s easier to leverage the tools available to you for large assemblies.


There are three pieces that make up the data of a SOLIDWORKS file. Each of these pieces is one of the ingredients that make up every SOLIDWORKS file. There is Parasolid, tessellation and parametric data in each SOLIDWORKS file.


The Parasolid aspect is the geometric engine that SOLIDWORKS itself is built on. This makes up the mathematical definition of the physical model. It’s known as the modeling kernel, which is the most fundamental component of any CAD software.

Bonus Tip: The name “Parasolid” should sound familiar to you because it’s an agnostic file type. You can use it to share files to those who find themselves unfortunately using a different CAD software. When sharing non-native CAD files, use the Parasolid file type. Since it’s the native modeling kernel for many CAD packages on the market, using this file type saves some data translation on the back end, which will give you a more robust file.


The tessellation data is the information used to paint the pixels on the screen. Think of this as the visual data of every external surface or face. 


The parametric data represents the features in your model. These are the steps or instructions the software uses to build your mode. These are the steps shown in your SOLIDWORKS FeatureManager.

Back to Assembly Modes

Each of the assembly modes is doing nothing more than loading a specific piece of the data from the SOLIDWORKS file. Now, with an understanding of what’s going on behind the scenes, it should make more sense why each Assembly mode has their limitations.

Large Design Review Mode

Large Design Review or LDR was introduced with SOLIDWROKS 2012. It essentially began as an environment with limited functionality. The CommandManager has only one ribbon and the FeatureManager looks quite different.

Take a look at the video below which shows LDR in action. The file takes nearly eight minutes to open fully resolved, but just seconds in Large Design Review mode. I assure you; the video is in real time.

LDR is a view-only tool which opens files instantly and offers a snappy way to view or review files. It loads only the graphics data, which limits its functionality to viewing. This is the most basic subset of data that SOLIDWORKS needs. LDR’s functionality has grown over the years to include things such as section views and measurements, but think of this as a way to look at and gain an understanding of your designs. As the name implies, it’s perfect for design review meetings!

Lightweight Components

Lightweight components were introduced in the last millennium with SOLIDWORKS 1998Plus. Besides LDR, using lightweight components is the best way to improve performance with large assemblies.

Lightweight components include both the tessellation data and the parasolid data. This means that instead of just viewing the model, you have access to the solid data as well, so you can leverage some traditional modeling tools. Lightweight components work inside the regular modeling environment you’re used to. Look for a feather superimposed on the component in the FeatureTree. Any combination of components can be resolved or lightweight, which empowers you to focus your resources on what you need to.

The typical SOLIDWORKS power user will load their assemblies using lightweight components and then will individually resolve the components as needed for making changes to the geometry. One way to think of lightweight mode is that you can essentially do everything except for making changes to the geometry.

Lightweight components saw some of the most epic improvements with SOLIDWORKS 2021. It was undoubtedly one of the greatest hits of SOLIDWORKS 2021 (check out the article here for the rest). Lightweight components have been improved so much that now there is really no reason to not open your assemblies in lightweight mode. You’ll get all the time savings without any extra effort, because now components are automatically resolved just by expanding them in the FeatureManager. It’s essentially been made transparent to the user, but if you didn’t know about it, you’d totally miss it.

So, do you want to get improved performance with your large assemblies? It isn’t rocket surgery; instead it’s simple.

Take the first step and update to the latest version of SOLIDWORKS. We can even say this is step zero. By updating to the latest version, you are really building the foundation needed for success when it comes to working with large assemblies. The next step is to take advantage of the assembly modes. Use Large Design Review mode and make lightweight components a part of the workflow.

Of course, there are countless tips and techniques for working with Large Assemblies, but as the saying goes: You have to walk before you can run. Maybe in this case, it’s the SOLIDWORKS Performance that crawls before you learn how to make it run by implementing these two tips and techniques.

Want to unlock even more performance? Stay tuned for more advanced tips on working with Large Assemblies in SOLIDWORKS.

To learn more about SOLIDWORKS, check out the whitepaper Developing Better Products on the Cloud.

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