V9 WIP .step is opened longer than v8

[m.oguz]

Hi all,

When I open .step file via V9 WIP, it takes longer than v8 latest release.
.step file contains wardrobe parts and some wardrobe fasteners.

rhino v8 sr31 release candidate
(8.31.26104.8181, 2026-04-14)

rhino v9 wip
(9.0.26104.12305, 2026-04-14)

Here are my results.
First one is v8, second one is V9 WIP.

opening .step: 1min 20sec vs 1min 37sec
setting rendered mode: 21sec vs 23sec
total: 1min 41sec vs 2 min

note: opening step file via WIP, it took over 3minutes 2 days ago. Now it takes 1 min 37 sec. I don’t know why.

I see general optimization topic but I think it has not been implemented for .step file

Rhino WIP Feature: General Optimization

I have spent a decent portion of the last few months identifying and fixing bottlenecks in Rhino performance. As a result, in many cases Rhino WIP runs significantly faster than Rhino 8 for many tasks. These include, but are not restricted to: Opening large files. Display performance for files with large numbers of objects. Saving speed for large files. General performance improvements for adding/modifying objects in large files. I am typically seeing speed improvements of about…

Systeminfo

Rhino 9 SR0 2026-4-14 (Rhino WIP, 9.0.26104.12305, Git hash:master @ 5bd7a4f16954bce589a148ccd941ced83b3638ad)
License type: Commercial, build 2026-04-14
License details: Stand-Alone
Expires on: 2026-05-29

Windows 11 (10.0.26200 SR0.0) or greater (Physical RAM: 64GB)
.NET 9.0.1

Computer platform: LAPTOP - Plugged in [65% battery remaining]

Non-hybrid graphics configuration using DirectX
Primary display: NVIDIA RTX 5000 Ada Generation Laptop GPU (NVidia) Memory: 16GB, Driver date: 10-29-2025 (M-D-Y). DirectX(11)
> Integrated accelerated graphics device with 4 adapter port(s)
- Windows Main Display is laptop’s integrated screen or built-in port

Secondary graphics devices.
Intel(R) UHD Graphics (Intel) Memory: 2GB, Driver date: 11-3-2025 (M-D-Y).
> Integrated graphics device with 4 adapter port(s)
- There are no monitors attached to this device.

DirectX Settings
Safe mode: Off

OpenBLAS: OpenBLAS 0.3.30 DYNAMIC_ARCH NO_AFFINITY Haswell MAX_THREADS=64.

Rhino plugins that do not ship with Rhino

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 9 WIP\Plug-ins\Commands.rhp “Commands” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 9 WIP\Plug-ins\UpdatesAndStatistics\UpdatesAndStatistics.rhp “UpdatesAndStatistics” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 9 WIP\Plug-ins\MeshCommands.rhp “MeshCommands” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoCycles.rhp “RhinoCycles” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 9 WIP\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 9 WIP\Plug-ins\SectionTools.rhp “SectionTools”

I have sent the file via private message.

Thank you in advance.

[martinsiegrist]

@m.oguz

opening .step: 1min 20sec vs 1min 37sec

I just did a test with a 105 MB file and I see a similar time difference. 2 min 17 seconds in Rhino 8 and 2 min 27 seconds in Rhino 9 WIP for opening the file (displayed in wireframe)

System Info

Rhino 9 SR0 2026-4-14 (Rhino WIP, 9.0.26104.12305, Git hash:master @ 5bd7a4f16954bce589a148ccd941ced83b3638ad)
License type: Commercial, build 2026-04-14
License details: Cloud Zoo
Expires on: 2026-05-29

Windows 11 (10.0.26200 SR0.0) or greater (Physical RAM: 128GB)
.NET 9.0.15

Computer platform: DESKTOP

Standard graphics configuration using DirectX
Primary display: NVIDIA RTX A5000 (NVidia) Memory: 24GB, Driver date: 12-19-2025 (M-D-Y). DirectX(11)

Accelerated graphics device with 4 adapter port(s)

• Windows Main Display attached to adapter port #0
• Secondary monitor attached to adapter port #1

Secondary graphics devices.
NVIDIA Quadro K2200 (NVidia) Memory: 4GB, Driver date: 12-19-2025 (M-D-Y).

Accelerated graphics device with 4 adapter port(s)

• There are no monitors attached to this device!

DirectX Settings
Safe mode: Off

OpenBLAS: OpenBLAS 0.3.30 DYNAMIC_ARCH NO_AFFINITY Zen MAX_THREADS=64.

Rhino plugins that do not ship with Rhino

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 9 WIP\Plug-ins\Commands.rhp “Commands” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 9 WIP\Plug-ins\UpdatesAndStatistics\UpdatesAndStatistics.rhp “UpdatesAndStatistics” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 9 WIP\Plug-ins\import_STEP.rhp “STEP Import”
C:\Program Files\Rhino 9 WIP\Plug-ins\MeshCommands.rhp “MeshCommands” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\IronPython\RhinoDLR_Python.rhp “IronPython” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoCycles.rhp “RhinoCycles” 9.0.26104.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 9 WIP\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 9 WIP\Plug-ins\SectionTools.rhp “SectionTools”

[m.oguz]

mine is also 101mb

[martinsiegrist]

I guess the file size itself is not the only relevant thing? We have the same graphics card except mine is not in a laptop

[m.oguz]

sure it depends on many things.
I hope Mcneel team will investigate it and make a fix for .step files.
You can share your .step file if you like, more investigable files makes WIP better I think

[martinsiegrist]

I’ll see if I have something I can share.

An improvement in Rhino 9 is the progress being printed in the command line.

On a 180 MB file from the same source containing similar geometry as in my 105 MB file it’s 3 min 33 seconds for Rhino 8 and 3 min 58 seconds for Rhino 9

[martinsiegrist]

I did another test with an example file from an IFC conversion. I found the steptools website looking for the source of my file and there are a few good files for testing:

Large Assembly Files

I tried the Ai-14R.stp engine file and my results were 3 minutes in Rhino 8 and 3 minutes 10 seonds in Rhino 9 WIP

In Rhino 8 I have ‘Display bad objects warning’ unchecked but I guess this does not make a difference when there are no bad objects.

[Guillermo_Varela]

Thanks for sending the file. I have checked it and I can reproduce the same time differences opening it on Rhino 8 and Rhino WIP. I have reported it to the developers but didn’t make it public to keep the file private.

[m.oguz]

Hi @Guillermo_Varela
, any progress on the issue?

[wim (Wim Dekeyser)]

Hi M -

@m.oguz

any progress on the issue?

From the developer:

Nothing that would impact file read time has changed in the Step import plugin between V8 and V9 so any change in time must be in functions called from the plugin. This is not likely to improve soon.

-wim