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STEP files and what is SolidWorks doing when it freezes?

Question asked by Checkcheck Master on May 16, 2019

He there, among other things I am wondering how you SolidWorks-users fight with STEP files. For me they are very time-consuming and takes the flow out of SolidWorks, this is my experience and the attempts to get it under control.

Please share your improvements and solutions. Does anyone has knowledge or experience about double the internal memory to for example 64 GB? And, are there video cards that can make a significant difference?


Since a few months I've got an engineering job where I need to work with lots of big STEP files. The company I work for is building Fire Trucks. We buy a truck with an 'empty' chassis and build it up with a fire body which makes it a Fire Truck. In the current now running project I have to deal with STEP files being exported out of Catia. Importing STEP files can be a real challenge I've experienced and once imported there is the challenge to keep the content running in your assemblies. 'Lots' and 'big' are relative understandings I realize but regarding the process time of the STEP files and later on the loading time of the created assemblies the terms are relevant for me. I've studied the import options within SolidWorks and got the idea I've got it under control. I learned, for example, it's important to 'import multiple bodies as parts' to avoid a part for every imported solid or surface, and that 'enable 3D interconnect' takes away the possibility to suppress or unsuppress instances in your SW assembly once imported. With suppressing not relevant details I try to end up with as light as possible assemblies to work with, and have the option to have the details when I need them by having a 'not suppressed' configuration. Also not every STEP file will import that easy I find out. Strange enough files who won't import or comes with errors once imported, will open normally in for example EDrawings or GrabCAD. As a workaround I've 'download as' the files in GrabCAD in ParaSolid format and open them in SW without problems and with much less process time, thank you GrabCAD. I've contacted the truck manufacturer and asked about the option to request less detail in the files, unfortunately the level of detail is simply in the original files and that's it. Exporting to ParaSolid would not be an option in Catia. As far as I know, opening Catia files in SW is only possible with a paid addin. The truck manufacturer normally export the files as STEP 242 with tessellated data. SW is not capable of handeling that tessellated data. SolidWorks MBD, a paid addin, is capable to 'import PMI data'. I find out, more or less by accident, my VAR therefore gives me a trial period, that the MBD product still needs some development, it came up with unsolvable errors when importing the STEP files, they made a support-ticket and that was it. Is Catia creating inferior STEP files that won't matter for GrabCAD or EDrawings or is it SolidWorks that make the mess? An attempt with one IGES file failed when try to open. Of course at first I doubt the machine working with. My VAR indicates the machine should not be the bottleneck, a new machine won't make the difference. We are talking about a HP Z240 with an Intel I7-6700K at 4.00 GHz and 32 GB installed in combination with a NVIDIA Quadro M2000, running SW2018. Our SW files are on a server, transfer speed seems okay. To ensure I've tried more than once to Pack and Go the files on the SSD C-drive which won't make the difference either. I've studied the options within SW about 'large assembly mode, 'lightweight' and 'Speed Pak' for example and I think I know how to handle them to get the most out of the system.

Btw, for me 'Speed Pak' doesn't really offer the solution, to me it looks nicer than it is, too often you want more out of the model than 'Speed Pak' allows. 


A direct question in these regarding SW behavior I do not understand entirely: I've assembled the truck cabin out of 10 STEP files using the method described above, GrabCAD, ParaSolid, SW and so on. The STEP/ParaSolid files varies in size between 200+ and 400+ MB each.The assemblies are oriented around the same origin which made it easy to put them in an assembly and minimize the amount of mates. The 'Total Cabin Assy.sldasm' file in unsuppressed state is 600+ MB in size. A zipped Pack and Go from the complete assembly approx. 1.7 GB. For me in my 'SW career' serious big files. Once the model is loaded in 'large assembly mode' with 'image quality' set to minimum, and visible on the screen it's good to manipulate. For example with the 3D mouse the model moves smoothly across the screen, fast moves are no problem either. But then, at times when you don't expect it, the model suddenly freezes, actually SW completely freezes. Sometimes it's a few seconds, say 2 or 3, after where the model can be moved again. Sometimes the freezing moments come in several steps one after the other and it can take just 10, 20 or more seconds before the model can be moved again. Both of these behaviors are very annoying, the last one really take the lead. When you click a mouse button the 'not responding' window appears indicating SW is busy with things. I'l try to monitor the internal memory in Windows Task Manger\Performance but doesn't tell me much. As said, it's annoying, especially that I don't see the trigger for the recalculations. What makes it that from nothing, at least so it seems, it must be frozen and apparently calculated? I' was not zooming in on more detail or something. Are there beter tools to monitor the internal and video memory? Do I still need a better video card? Wil make 64 GB instead of 32 GB the difference? I like to know.

Thanks for reading, I'm looking forward your reactions.