nemo insanely slow when many files in directory

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elmar roberg
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Re: nemo insanely slow when many files in directory

Post by elmar roberg »

I will differ with some of the writers.
I too occasionally suffer from the problem. But suspect it is not OS, because whenever Nemo hangs, I simply open Double Commander and get instantaneous results.

Petermint
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Re: nemo insanely slow when many files in directory

Post by Petermint »

One experiment would be interesting. Open the System Monitor and watch the processor usage while nemo is running slow. Is Nemo locked into one processor?

If Nemo is developed using a modern programming language/approach, the thumbnail and other processes could happen in the background using other cores. I do not have a directory with enough files to create the problem. I do see a similar problem in other software where the SSD is faster than the software but the software uses only one core.

Petermint
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Re: nemo insanely slow when many files in directory

Post by Petermint »

Some replies suggest reorganising 50000 files into subdirectories. I have the slow Nemo problem with 50000 files organised into subdirectories, suggesting that the reorg is not a complete solution. Nemo 4.4.2.

The example I am looking at now has dozens of subdirectories with some of them having dozens of subdirectories. Nemo is using 147 MB. I do not know if it is caching everything or depending on the OS cache. There is 4 GB of memory spare for Nemo and OS caching.

Nemo 4 has an option in preferences to switch off thumbnails. I switched that off. Everything is less slow but still too slow.

Meld has a similar problem with displays of long file lists but that is understandable as Meld uses Python.

I do not know how Nemo is programmed. I wrote some C + GTK 3.22 code to do something similar. The GTK code for displaying lists of boxes is stupidly slow when there is more than 10 ~ 20 items in a list. I had to rewrite the code to maintain the lists outside of GTK and only use GTK to display a small selection within a list.

I developed the same display using a PHP Web page and it runs at full speed with no problems. If Nemo uses GTK 3, that could be one part of the problem.

Petermint
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Re: nemo insanely slow when many files in directory

Post by Petermint »

Another speed observation. I opened a directory I had looked at earlier. I selected some files. I had to wait 1~2 seconds before the mouse click resulted in a file display changing from the white unselected state to the green selected state. Nemo was performing a lot of work in the background despite having visited this directory before.

I deselected the list and selected the files a gain. This time it was instant. Nemo appears to spend a lot of time in the background doing something with the file list for the directory but then throws all that away when you move to a different directory. Nemo has to perform all the work again when you return to the fist directory.

Perhaps there a setting somewhere in Nemo to tell it to use more of the available Gigabytes or maybe a compile option.

Petermint
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Re: nemo insanely slow when many files in directory

Post by Petermint »

https://github.com/linuxmint/nemo/issues/1907
I switched off all Nemo extensions to get the old Nemo speed back but it is useless without some of those extensions.
I switched Fileroller back on without slowing down Nemo. I think Fileroller only does stuff when you right click.
I have no use for the share, colour, or emblem plugins and they seem to not make much difference.
That leaves the Nemo Media Columns plugin as the time waster.
More testing needed.

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smurphos
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Re: nemo insanely slow when many files in directory

Post by smurphos »

Petermint wrote:
Sun Mar 22, 2020 1:54 am
That leaves the Nemo Media Columns plugin as the time waster.
It's definitely a time waster in my experience. If simple access to media info in the File manager is required and no need to sort by it I always recommend nemo-mediainfo-tab instead - https://launchpad.net/~caldas-lopes/+archive/ubuntu/ppa, which provides info on individual files via an extra tab on the Properties dialog.
For custom Nemo actions, useful scripts for the Cinnamon desktop, and Cinnamox themes visit my Github pages.

Petermint
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Re: nemo insanely slow when many files in directory

Post by Petermint »

no need to sort
That is a sticking point. I sometimes need to sort media info. I will leave the extension installed and switched off. When I do need that data displayed and sorted, I will switch the extension on.

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