SOLVED: darktable 4.4.2 - Windows performance

getting a “get more RAM or lower threads for export darktable 4.4.2”

Where can I find the “lower thread” change mentioned here?

  • RAM problem is being solved by building a Ryzen 7, DDR3 8GB, multiple HDD desktop system - but im still 2-3 months away from completing that

Currently running darktable on celeron 1.1GHz 4core, 4GB RAM (411MB available LMAO) cheap laptop

looking for where to change my settings on darktable 4.4.2 to lower this threads for export - i think this is to do with my previews, as Im working with CR2 RAW files exclusively

thanks for any help to this newcomer to PIXLS.US - seems to be the most active forum for darktable :slight_smile:

  • manualphotog

solved : i changed the preview quality to VGA , for now :slight_smile: (it was on Always, something I had put a while back when using darktable without other things running)

4.4.2 set to VGA not ALways

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I think on a limited system I would set them to never…

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I think that would be:

-t <num openmp threads>
limit number of openmp threads to use in openmp parallel sections.
(darktable 4.6 user manual - darktable)

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No. Your screenshot shows:

  • use raw file instead of embedded JPEG from size: VGA

    if the thumbnail size is greater than this value, it will be processed using raw file instead of the embedded preview JPEG (better but slower).
    if you want all thumbnails and pre-rendered images in best quality you should choose the always option.

So, I you enlarge the thumbnails of the lighttable, and the size is at least VGA (640 x 480 px), instead of using the JPG embedded by the camera, the whole raw file will be processed. This setting is only used on unprocessed (never opened) files; once you process something, the raw file is used regardless of size.

  • high quality processing from size: VGA

    if the thumbnail size is greater than this value, it will be processed using the full quality rendering path (better but slower).
    if you want all thumbnails and pre-rendered images in best quality you should choose the always option.
    (more comments in the manual)

This means when you want to switch from a quicker way of processing the raw file to create the thumbnail. As soon as the thumbnail size reaches that size, the slower, but more exact method will be used.

Read darktable 4.6 user manual - lighttable

Read also:
https://darktable-org.github.io/dtdocs/en/preferences-settings/processing/
https://darktable-org.github.io/dtdocs/en/special-topics/mem-performance/

you are right @kofa and thanks for explaining it all aswell - makes sense now.

In that, I moved from “always” to “VGA” - however as you explained, that means as soon as the thumbnail hits VGA size on my screen, it moves to rendering with High Quality (which then slows my laptop system down and/or crashes darktable).

I have further adjsuted to moved this value on my screenshot to “4K”, so it will do lower quality on the preview and thumbnails pretty much all the time, considering my laptop isnt 4K, but my 8.2MP image at 100% could be considered 4K size.

Its a good balance for performance as im usually at 60%-85% view or in Fit/Fill size for the main image.

Looking forward to the main build ---- Ryzen 5 or 7 system 8GB with GFX, a SSD 500GB and then multiple HDD; planning to run Mint Cinnamon.

Blockquote… on a limited system …set them to never…

but, but
My Eyes!!! :wink:

more serious answer - I often use preview pane to see overall image effects, tones, shadows etc instead of zoomin out, so i need some decent preview image capability, but with “Always”, i was crashing with a browser running concurrently with darktable lol. “VGA” helped, but not enough ae

Try that -t option on the command line, like darktable -t 1.

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This option (under preferences → processing) is also worth checking out (it does not affect exports, so you may run out of memory there if you don’t reduce the number of threads / add more RAM):