For a little while now, I have found that Clusters are not really usable anymore in Grasshopper2. Creating one is ok, but as soon as one try to edit it, the whole canvas becomes very VERY slow and laggy. Closing cluster to go back to parent file is kind of possible, but cluster editor is really closed only after a while.
Regarding Clusters, it would also be nice to have a visual indication we’re inside one : the blue background of GH1 was quite effective in that sense.
I totally agree, and I’ve noticed the same thing!
Are we the only ones experiencing this ? This lagginess really makes clusters unusable for me..
I have not experienced it myself, but if you can share a cluster where this is happening for you I can test it.
It just happens with any cluster I create, no matter what’s inside. The cluster itself runs smoothly, but if I try to edit it, everything in Rhino becomes laggy.
Closing Cluster Editing is also laggy, and I need some time to get back Rhino and GH2 snappiness.
SystemInfo
Rhino 9 SR0 2026-8-25 (Rhino 9 BETA, 9.0.26237.15343, Git hash:master @ 96051fb40f8d55297d947c054b9d2f7c03d4bdeb)
License type: Educational Lab License, version 2026-08-25
License details: Cloud Zoo
Expires on: 2026-10-09
Windows 11 (10.0.26100 SR0.0) or greater (Physical RAM: 16GB)
.NET 10.0.9
Computer platform: LAPTOP - Plugged in [100% battery remaining]
Non-hybrid graphics configuration using DirectX
Primary display: Radeon Pro 560 (AMD) Memory: 4GB, Driver date: 8-19-2024 (M-D-Y). DirectX(11)
> Integrated accelerated graphics device with 6 adapter port(s)
- Windows Main Display is laptop's integrated screen or built-in port
- Secondary monitor attached to adapter port #1
Secondary graphics devices.
None found.
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
C:\Users\Felix\AppData\Roaming\McNeel\Rhinoceros\packages\9.0\Karamba3D\3.1.60519\net8.0-windows\Karamba3D_LicensePlugin_Rhino8.rhp "Karamba3DLicense"
Rhino plugins that ship with Rhino
C:\Program Files\Rhino 9 WIP\Plug-ins\Commands.rhp "Commands" 9.0.26237.15343
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk.rhp "Renderer Development Kit"
C:\Program Files\Rhino 9 WIP\Plug-ins\3dxRhino.9.rhp "3DxRhino.9"
C:\Program Files\Rhino 9 WIP\Plug-ins\UpdatesAndStatistics\UpdatesAndStatistics.rhp "UpdatesAndStatistics" 9.0.26237.15343
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoRenderCycles.rhp "Rendu de Rhino" 9.0.26237.15343
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk_etoui.rhp "RDK_EtoUI" 9.0.26237.15343
C:\Program Files\Rhino 9 WIP\Plug-ins\NamedSnapshots.rhp "Snapshots"
C:\Program Files\Rhino 9 WIP\Plug-ins\MeshCommands.rhp "MeshCommands" 9.0.26237.15343
C:\Program Files\Rhino 9 WIP\Plug-ins\Grasshopper2\net48\Grasshopper2Plugin.rhp "Grasshopper2" 9.0.26237.15343
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoCycles.rhp "RhinoCycles" 9.0.26237.15343
C:\Program Files\Rhino 9 WIP\Plug-ins\Displacement.rhp "Displacement"
C:\Program Files\Rhino 9 WIP\Plug-ins\SectionTools.rhp "SectionTools"
Thanks, I’ll dig through all the code that only runs while editing clusters to see if anything there is capable of clogging up the UI thread.
As a quick test, does it still happen when you disable the solver? (Solver state is available in the menu and on the status bar). I expect it has nothing to do with this issue, but since I don’t have any good ideas yet, may as well rule it out.
Indeed, disabling the solver does not help.
But I discovered another bug, should I open another thread ? With solver disabled, new components added to the canvas through search and keyboard are added transparently (they react to clicks and tooltip, but are not visible before I click anywhere on the canvas)
No need, logged under RH-98103.
I have found a somewhat suspicious bit of code which could explain the slowdown, but since I cannot replicate the issue I do not know if it fixed anything. The next release no longer has this code which potentially causes continuous redraws.
I also added a debugging feature which shows some statistics in the top right corner of the canvas. It can be shown/hidden via the View menu. This should all become available in the next Rhino9 Beta, which is usually released on Tuesdays.
It includes the total number of times the canvas has been redrawn, the average framerate for the very recent history, the time it took to draw the last frame, and whether the canvas is in normal or cluster mode.
Hello @DavidRutten, I confirm the slowness of Cluster Editor is fixed 
Thanks for the responsiveness !