Extremely slow deletion time for massive amount of objects #53163

New Issue

System Information
Win 7 64 bit

Blender Version
2.78c

Deleting massive amount of objects is crazy slow; a user suggested to post it as a bug, possibly memory leak?

I made some tests with the same scene in Blender and 3ds Max:
Deletion of ~22.000 objects in Max is 2 minutes and 10 secs.
In Blender I shut it down after 1 and a half hour and let it happen while I was sleeping at night.

I don't know if it is a bug or just the dependency graph's default behavour; hopefully if the last, it will be addressed in 2.8.

Thanks

**System Information** Win 7 64 bit **Blender Version** 2.78c Deleting massive amount of objects is crazy slow; a user suggested to post it as a bug, possibly memory leak? I made some tests with the same scene in Blender and 3ds Max: Deletion of ~22.000 objects in Max is 2 minutes and 10 secs. In Blender I shut it down after 1 and a half hour and let it happen while I was sleeping at night. I don't know if it is a bug or just the dependency graph's default behavour; hopefully if the last, it will be addressed in 2.8. Thanks

Changed status to: 'Open'

Added subscriber: @AlmaTalp

Added subscriber: @JoshuaLeung

It is a known issue that Blender does not work that well with a large number of objects. That said, to be able to figure out what may be going on here, it would help to have a few extra pieces of information:

How are you deleting these objects? Using an operator in the 3D view, from the outliner, or using the console or a script?
How complex are these objects? Are they meshes with a lot of vertices, or are they simple (i.e. similar to a cube/box)?
Do you have any animation, physics, drivers/constraints, modifiers, nodetrees, etc. enabled on any of these objects? Are any of these part of a rigidbody sim? Are particles and duplis used anywhere?
What addons do you have running?
How much RAM does your machine have, and how much memory is Blender using?
Can you work with these objects at a resonable speed in Blender (if not deleting them)? e.g. selecting, moving, and doing animation playback?

It is a known issue that Blender does not work that well with a large number of objects. That said, to be able to figure out what may be going on here, it would help to have a few extra pieces of information: * How are you deleting these objects? Using an operator in the 3D view, from the outliner, or using the console or a script? * How complex are these objects? Are they meshes with a lot of vertices, or are they simple (i.e. similar to a cube/box)? * Do you have any animation, physics, drivers/constraints, modifiers, nodetrees, etc. enabled on any of these objects? Are any of these part of a rigidbody sim? Are particles and duplis used anywhere? * What addons do you have running? * How much RAM does your machine have, and how much memory is Blender using? * Can you work with these objects at a resonable speed in Blender (if not deleting them)? e.g. selecting, moving, and doing animation playback?

Hello Joshua, thanks.

Infos:

I delete them in the 3d view with the delete keyboard button.
The complexity is various, but most of them could be considered as low-poly/ultra low-poly (but not at the 'box/cube' level low poly).
There are about 4.000 base objects, the remaining number of ofjects are instances of these.
Only modifier is the Triangulate on some of them (not really relevant, like on 2% of the objects). No sims, no particles.
As nodetree I do not know what you mean.
I have tons of addons installed; I don't know if is there an easy way to list them?
What could be relevant - for a short list -:

Name Panel
Asset Sketcher
MeshLint
MultiEdit
Multi Object UV Editing

32 GB RAM.

Scene uses about 10GB.

Overall FPS is about 8-10 in wire and solid mode (walkthrough cam only, no other animation). In GLSL mode it is very slow (0,5-3 FPS; even change viewport to GLSL is very slow)
I use a Radeon RX480 8GB for display and GTX 1070 8GB to render.

Selection speed is noticeable, but not extremely slow when multiple objects are selected.
Moving objects is OK, but - of course - not as smooth as in simple scenes.
Adding objects is slow. Inserting a keyframe to a camera is slow.

Hello Joshua, thanks. Infos: 1. I delete them in the 3d view with the delete keyboard button. 2. The complexity is various, but most of them could be considered as low-poly/ultra low-poly (but not at the 'box/cube' level low poly). There are about 4.000 base objects, the remaining number of ofjects are instances of these. 3. Only modifier is the Triangulate on some of them (not really relevant, like on 2% of the objects). No sims, no particles. As nodetree I do not know what you mean. 4. I have tons of addons installed; I don't know if is there an easy way to list them? What could be relevant - for a short list -: - Name Panel - Asset Sketcher - MeshLint - MultiEdit - Multi Object UV Editing 5. 32 GB RAM. Scene uses about 10GB. 6. Overall FPS is about 8-10 in wire and solid mode (walkthrough cam only, no other animation). In GLSL mode it is very slow (0,5-3 FPS; even change viewport to GLSL is very slow) I use a Radeon RX480 8GB for display and GTX 1070 8GB to render. - Selection speed is noticeable, but not extremely slow when multiple objects are selected. - Moving objects is OK, but - of course - not as smooth as in simple scenes. - Adding objects is slow. Inserting a keyframe to a camera is slow.

Ok. Two other things I forgot to mention:

Have you tried running newer versions of Blender (i.e. 2.79) and/or running Blender from the commandline with the --factory-startup option? The factory startup option will disable all addons, and can help us narrow down if it's one of the addons causing problems.
Could you upload (or link if the file is several GB's) to a file where this problem occurs.

Ok. Two other things I forgot to mention: * Have you tried running newer versions of Blender (i.e. 2.79) and/or running Blender from the commandline with the `--factory-startup` option? The factory startup option will disable all addons, and can help us narrow down if it's one of the addons causing problems. * Could you upload (or link if the file is several GB's) to a file where this problem occurs.

Ok. I'm running the factory clean Blender 2.79 test now.

BTW it is a scene I work on from 2.74 with similar problems; I also tested deletion with some 2.80 builds and still no joy, it is slow.
IMHO it is related to known limitations and it would be great to see enhancements here. That is why I tested 2.80, but I haven't seen any yet.

Related to the scene: unfortunately I cannot share it.

Ok. I'm running the factory clean Blender 2.79 test now. BTW it is a scene I work on from 2.74 with similar problems; I also tested deletion with some 2.80 builds and still no joy, it is slow. IMHO it is related to known limitations and it would be great to see enhancements here. That is why I tested 2.80, but I haven't seen any yet. Related to the scene: unfortunately I cannot share it.

Added subscriber: @VukGardasevic

@AlmaTalp to list all the enabled add-ons it's enough to attach the system-info.txt generated from the Help> Save System Info menu by dragging and dropping the whole .txt file into the comment field (introduced in Blender 2.79).

@AlmaTalp to list all the enabled add-ons it's enough to attach the `system-info.txt` generated from the `Help> Save System Info` menu by dragging and dropping the whole .txt file into the comment field (introduced in Blender 2.79).

I shut it down again, still not finished. (clean setup)

@Vuk: thanks for the tip.

I shut it down again, still not finished. (clean setup) @Vuk: thanks for the tip.

I made a new test, also here is the link for a testfile I made.

Times:

3ds Max time: 28 sec
Blender 2.79 (clean): 13 minutes 45 secs

Testfile: https://ufile.io/imxw5

I made a new test, also here is the link for a testfile I made. Times: 3ds Max time: 28 sec Blender 2.79 (clean): 13 minutes 45 secs Testfile: https://ufile.io/imxw5

Ok, some updates with test file:

Deletion times:

Cinema4D (R19): 15 sec
3DS Max (2012): 30 sec
Maya (2018): 13 min 40 sec
Blender (2.78): 13 min 45 sec
MODO (11): 26-27 min
MODO (9): 40 min

Ok, some updates with test file: Deletion times: Cinema4D (R19): 15 sec 3DS Max (2012): 30 sec Maya (2018): 13 min 40 sec Blender (2.78): 13 min 45 sec MODO (11): 26-27 min MODO (9): 40 min

Interesting... we're certainly not the worst here, but there's also cleary some room for improvement too :)

Yep, Cinema and MODO both shocked me (different way).

From Blender aspect the problem is that in real life scenario with my real scene the deletion take hours which is insane.
I create all my contents in Blender and I also import/export 10Ks of objects between apps. A 10x speed up would solve all my problems and put Blender to the top3. As scene organization gets a boost in 2.8 and many of my former issues has been solved in the last years I have a huge trust in Blender's future. :)

BTW the friend of mine who made the MODO test also delivered this data to Foundry to make them think about it!

Yep, Cinema and MODO both shocked me (different way). From Blender aspect the problem is that in real life scenario with my real scene the deletion take hours which is insane. I create all my contents in Blender and I also import/export 10Ks of objects between apps. A 10x speed up would solve all my problems and put Blender to the top3. As scene organization gets a boost in 2.8 and many of my former issues has been solved in the last years I have a huge trust in Blender's future. :) BTW the friend of mine who made the MODO test also delivered this data to Foundry to make them think about it!

Added subscriber: @mont29

Changed status from 'Open' to: 'Archived'

Cannot even open your file here, not enough RAM on my laptop…

That being said, having thousands of data-blocks in Blender is known to be an issue, either when adding or removing some (for different reasons). We are aware of the issue, but this is not considered a bug currently, rather a TODO. See e.g. D2910 (which shall solve a lot of the 'add new ID' slowness issue).

Removing being slow has another cause though - the fact that for each ID (object or whatever else) you remove, we have to go over the whole Main database of IDs to check its potential relations with them. Solving that would likely require to add some kind of 'bulk removal' process, nice TODO, but again, not a bug. ;)

Cannot even open your file here, not enough RAM on my laptop… That being said, having thousands of data-blocks in Blender is known to be an issue, either when adding or removing some (for different reasons). We are aware of the issue, but this is not considered a bug currently, rather a TODO. See e.g. [D2910](https://archive.blender.org/developer/D2910) (which shall solve a lot of the 'add new ID' slowness issue). Removing being slow has another cause though - the fact that for each ID (object or whatever else) you remove, we have to go over the whole Main database of IDs to check its potential relations with them. Solving that would likely require to add some kind of 'bulk removal' process, nice TODO, but again, not a bug. ;)

Thanks, Bastien.
Do you have any idea when overall performance will be better? Will 2.8 bring change related to this (my former tests did not show improvements).

Thanks!

Thanks, Bastien. Do you have any idea when overall performance will be better? Will 2.8 bring change related to this (my former tests did not show improvements). Thanks!

Currently no, 2.8 has no difference compared to master on this field yet. But if/when such a new development is done, it will most likely happen in 2.8 now, since objects handling is quite different between both branches.

Hello Bastien,

I grabbed the 2.8 beta and made the test process again.

These were the former results:

Deletion times:

Cinema4D (R19): 15 sec
3DS Max (2012): 30 sec
Maya (2018): 13 min 40 sec
Blender (2.78): 13 min 45 sec
MODO (11): 26-27 min
MODO (9): 40 min

The beta deletes the scene in more than 32 minutes what makes Blender 2.8 the SLOWEST among all the 3d applications.
Is there any plan to speed it up to the original level?

(God, I think this the 3rd time when I realize that some very important features were better before 'enhancements' :D )

Hello Bastien, I grabbed the 2.8 beta and made the test process again. These were the former results: Deletion times: Cinema4D (R19): 15 sec 3DS Max (2012): 30 sec Maya (2018): 13 min 40 sec Blender (2.78): 13 min 45 sec MODO (11): 26-27 min MODO (9): 40 min The beta deletes the scene in more than 32 minutes what makes Blender 2.8 the SLOWEST among all the 3d applications. Is there any plan to speed it up to the original level? (God, I think this the 3rd time when I realize that some very important features were better before 'enhancements' :D )

Ok, it is 2021 almost, the current deletion time is about 24 minutes with Blender 2.91. When will this issue be solved?

Added subscriber: @ChristophWerner

In #53163#1071080, @AlmaTalp wrote:
Ok, it is 2021 almost, the current deletion time is about 24 minutes with Blender 2.91. When will this issue be solved?

I've the same problem with 2.92. It makes me crazy to wait for deleting objects. I've a complex scene, too.
I don't know why Blender seem to use just one CPU core to delete objects. I have an Ryzen Threadripper with 32 cores... 31 cores does nothing while deleting.

This needs to fixed.

> In #53163#1071080, @AlmaTalp wrote: > Ok, it is 2021 almost, the current deletion time is about 24 minutes with Blender 2.91. When will this issue be solved? I've the same problem with 2.92. It makes me crazy to wait for deleting objects. I've a complex scene, too. I don't know why Blender seem to use just one CPU core to delete objects. I have an Ryzen Threadripper with 32 cores... 31 cores does nothing while deleting. This needs to fixed.

As a reminder, the way to mass-delete a huge anount of objects is to use the Outliner's Delete operation (from its right-click menu).

Deleting objects from the 3DView does a lot of extra 'smart' processing that will make it extremely slow in case of mass-deletion (or even removing a few objects from a massive collection of those).

As a reminder, the way to mass-delete a huge anount of objects is to use the Outliner's `Delete` operation (from its right-click menu). Deleting objects from the 3DView does a lot of extra 'smart' processing that will make it extremely slow in case of mass-deletion (or even removing a few objects from a massive collection of those).

In #53163#1129644, @mont29 wrote:
As a reminder, the way to mass-delete a huge anount of objects is to use the Outliner's Delete operation (from its right-click menu).

Deleting objects from the 3DView does a lot of extra 'smart' processing that will make it extremely slow in case of mass-deletion (or even removing a few objects from a massive collection of those).

Thank you for the reminder, but I do it already via the outliner and it's still slow... And "yes", I have a lot of Collections.

> In #53163#1129644, @mont29 wrote: > As a reminder, the way to mass-delete a huge anount of objects is to use the Outliner's `Delete` operation (from its right-click menu). > > Deleting objects from the 3DView does a lot of extra 'smart' processing that will make it extremely slow in case of mass-deletion (or even removing a few objects from a massive collection of those). Thank you for the reminder, but I do it already via the outliner and it's still slow... And "yes", I have a lot of Collections.

Maybe then a less 'smart' way is better.
The deletion time in 3Ds Max 2012 (!) is 30 sec, in C4D is 15 sec for the very same scene Blender 2.8x needs almost 20 minutes.

Maybe then a less 'smart' way is better. The deletion time in 3Ds Max 2012 (!) is 30 sec, in C4D is 15 sec for the very same scene Blender 2.8x needs almost 20 minutes.

Added subscriber: @thierrykobyleski

Added subscriber: @Renderbicks

I actually confirm this issue in Blender 3.5. Deleting takes extremely long. I am not waiting for around 30 minutes and still deleting (or frozen).

In #53163#1129629, @ChristophWerner wrote:

In #53163#1071080, @AlmaTalp wrote:
Ok, it is 2021 almost, the current deletion time is about 24 minutes with Blender 2.91. When will this issue be solved?

I've the same problem with 2.92. It makes me crazy to wait for deleting objects. I've a complex scene, too.
I don't know why Blender seem to use just one CPU core to delete objects. I have an Ryzen Threadripper with 32 cores... 31 cores does nothing while deleting.

This needs to fixed.

Steffen Dünner has a workaround to delete a lot of models within a minute:

Select Collection (or files)
Unlink (in all your scenes if you have multiple scenes in your file)
Purge

> In #53163#1129629, @ChristophWerner wrote: >> In #53163#1071080, @AlmaTalp wrote: >> Ok, it is 2021 almost, the current deletion time is about 24 minutes with Blender 2.91. When will this issue be solved? > > I've the same problem with 2.92. It makes me crazy to wait for deleting objects. I've a complex scene, too. > I don't know why Blender seem to use just one CPU core to delete objects. I have an Ryzen Threadripper with 32 cores... 31 cores does nothing while deleting. > > This needs to fixed. Steffen Dünner has a workaround to delete a lot of models within a minute: - Select Collection (or files) - Unlink (in all your scenes if you have multiple scenes in your file) - Purge

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Extremely slow deletion time for massive amount of objects #53163