New in SOLIDWORKS 2023: Large Assemblies Open Four Times Faster

If you do not have the patience to read long blog posts, we have great news: this article could be summarized by one screenshot:

Figure 1. Assembly open progress indicator reporting opening time in SW2023 vs SW 2022.

For many SOLIDWORKS users the best enhancement in SOLIDWORKS 2023 will be the ability to open large assemblies three to five times faster than before. For the drawings of such assemblies, the increase in performance is even more impressive: five to ten times faster. SOLIDWORKS is not one to brag, however. You will find little mention of this most important enhancement in the What’s New 2023 document.

There are very few things more frustrating for SOLIDWORKS users and their managers than having to wait for large assemblies to open, especially assemblies containing components with many complex imported features. Anyone who works in the automotive, aerospace or defense industries needs to incorporate components imported from STEP or IGES files that have thousands of bodies with tens of thousands of complex faces.

Throughout the years, especially during the submissions and voting phases for the 3DEXPERIENCE World Top Ten Ideas List, there were many votes for the SOLIDWORKS Product Definition (PD) Team to spend its R&D budget more on increasing performance and stability rather than on adding new features.

Improving performance is a nice request, easy to express, but vague. There is not one thing that needs addressing but rather several requiring distinct modules to be recoded. If all enhancement requests made by SOLIDWORKS users would be apples in a tree, the PD Team could focus on harvesting the biggest and ripest—not necessarily the lowest hanging.

Many performance-related enhancements have been unlocked in the last four years:

What about the lowest hanging, ripest and beautiful golden apple, about which we wrote last August, where we reported on the impact of large number of face-level appearances on opening time and graphics-generation time?

Figure 2. The impact of face-level appearances on opening time and graphics computation time.

Why was SOLIDWORKS so slow in processing large numbers of face and body-level appearances? The explanation lies in how information is read from a part file and loaded into RAM during the assembly opening process.

Most users believe that if the size of a part file is 100 MB, SOLIDWORKS will copy that amount of data in the RAM and move on to load the next component of the assembly. That is not true.

First, a SOLIDWORKS file is compressed (think ZIP files) so it needs unzipping before it is read. Then SOLIDWORKS performs a large number of small reads from the part file in order to grab the information that is relevant for the assembly. Imagine this dialog between the software and the part file:

And even worse, all this work was done by a single core of the CPU. As shown in Figure 2, the result was a component loading time that was 20 times longer than when the part had no appearances.

With such a great potential for improving performance, why was this problem not submitted as an enhancement for the Top 10 list? Very simple: most users affected simply thought that this is “normal.” After all, everyone—other than readers of and the students of Trimech’s Large Assembly and Drawing Workshop—knows that SOLIDWORKS is slow when working with imported geometry. So, creating an enhancement request for this scenario did not happen.

When Fixing a Bug is Equivalent to Implementing an Enhancement

The good news is that enhancement requests are not the only ways to log ideas for improving the software. Sometimes a great enhancement can be reported under the form of a bug report (SPR).

This is what got logged under SPR 1227113: Graphics – Display, Parts – Open: Performance: File specific: 2014 file to 2021 file migration issue. This is a very cryptic description. Fortunately, the experienced applications engineers from the Technical Support team sensed the potential for unlocking performance, so they flagged the SPR as “critical.”

Figure 3. Solving a critical SPR turned into the biggest enhancement in SOLIDWORKS 2023.

Translation: Starting with SOLIDWORKS 2023 the performance is drastically increased for parts with large number of imported features and large number of face-level and body-level appearances, assemblies containing such parts and drawings containing such parts.

The performance increases for switching from drawing to model and back were noticed during the 2023 BETA Testing period:

Part and Assembly Environments:

  • File open
  • Configuration change
  • Apply/Modify/Remove appearances
  • Rollback/Roll forward
  • Graphics Regeneration


  • File open
  • Drawing Views update
  • Changing sheets
  • Graphics Regeneration

It is interesting that after SOLIDWORKS 2023 was installed, we read the What’s New manual and found only three lines about assembly performance improvements:

Figure 4.

There is nothing else about reducing assembly opening times in this document.

Testing Setup

To test the new version, we chose a file known to greatly tax the CPU for both single-core and multi-core processing.

Figure 5.

All files were saved in SOLIDWORKS 2022 version.


The workstation we chose is the latest 15” Dell Precision laptop with the following configuration:

Figure 6. Dell Precision 5570.

SpecsDell Precision 5570
OSWindows 11 Professional
CPU12th Gen Intel(R) Core(TM) i9-12900H Base frequency: 2.5GHz Turbo frequency: 5.0GHz Physical cores: 6 Performance + 8 Efficient


For the test we used Windows 11 and installed both SOLIDWORKS 2022 SP4.0 and SOLIDWORKS 2023 PR1 on the workstation.


To compare the differences in performance between SOLIDWORKS 2022 and 2023 we followed this protocol.

  1. Ensured that the system settings will allow us to open the assembly in resolved mode.

Figure 7. System Options for SOLIDWORKS 2022.

Figure 8. System Settings for SOLIDWORKS 2023.

  1. Reboot the machine.
  2. Wait 10 minutes to ensure all starting processes are finalized.
  3. Start SOLIDWORKS 2022.
  4. Open the assembly in SOLIDWORKS 2022.
  5. Capture Opening time from the Assembly Open Progress Indicator.

Figure 9. SOLIDWORKS 2022 SP4.0 – Open Time.

  1. Capture Graphics Generation Time using Performance Evaluation/Assembly Rebuild Report.

Figure 10. SOLIDWORKS 2022 SP4.0 – graphics generation time.

  1. Reboot the machine.
  2. Wait 10 minutes to ensure all starting processes are finalized.
  3. Start SOLIDWORKS 2023.
  4. Open the assembly in SOLIDWORKS 2023.
  5. Capture opening time from the Assembly Open Progress indicator.

Figure 11. SOLIDWORKS 2023 PR1 – Open time.

  1. Capture graphics generation time using performance evaluation/assembly rebuild report.

Figure 12. SOLIDWORKS 2023 PR1 – graphics generation time.

The difference in performance is spectacular.

Figure 13. SOLIDWORKS 2023 is three times faster opening the assembly.

Figure 14. SOLIDWORKS 2023 computes graphics-triangles 18% faster than SOLIDWORKS 2022.

It is worth noting that for slower computers, the differential in performance is even higher. For example, doing the same test on a Dell Precision 5560, SOLIDWORKS 2023 opened the assembly four times faster than 2022.

SOLIDWORKS 2023 vs 2022 – Large Assembly Opening Race

If you want to see the two versions of SOLIDWORKS racing to open this assembly, watch this video. It is worth mentioning that recording the screen slowed down the opening process, thus the numbers differ from the screenshots above.


These are the types of enhancements users like the most. Simply upgrade SOLIDWORKS to the latest version and suddenly assembly files open several times faster, while the graphics computation lag diminishes significantly.

SOLIDWORKS 2023 is a game changer for working with such assemblies. Upgrade as soon as your IT department completes its evaluation of the new version.

About the Author

As an Elite AE and Senior Training and Process Consultant, working for TriMech Solutions, Alin Vargatu is a Problem Hunter and Solver.

He has presented 33 times at 3DEXPERIENCE World and SOLIDWORKS World, twice at SLUGME and tens of times at SWUG meetings in Canada and the United States. His blog and YouTube channel are well known in the SOLIDWORKS Community.

In recognition for his activity in the SOLIDWORKS Community, at 3DEXPERIENCE World 2021, the SWUGN (SOLIDWORKS User Group Network) awarded the SOLIDWORKS AE of the Year title to Alin Vargatu.

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