Lightroom Classic: JPEG Mini standalone is multicore but as a LR plugin, it's constrained to one core

  • 1
  • Idea
  • Updated 1 month ago
  • (Edited)
I use JPEG Mini and "JPEG Mini plugin for LR". Lightroom totally hamstrings the software by only allowing one core to work on the export group. 

Tested with 61 NEF Nikon D750 24MP files. 6-core i7 8700K at 4.9GHz

LR + JPEG Mini plugin export combo
5:06

LR export then drag into JPEG Mini standalone
2:40s + 18s = 2:58


Please fix. Unleash the beast.
Photo of seanhoyt-dot-art

seanhoyt-dot-art

  • 288 Posts
  • 49 Reply Likes

Posted 1 month ago

  • 1
Photo of Just Shot Me

Just Shot Me

  • 233 Posts
  • 61 Reply Likes
Why not post this to the plugin writers forums. IMHO it has nothing to do with LR. LR does not control the number of CPU cores used for anything other than LR itself. And even then it is up to the OS to give up CPU time.
Photo of Rikk Flohr

Rikk Flohr, Official Rep

  • 4437 Posts
  • 872 Reply Likes
Have you contacted the plugin manufacturer for support regarding this?
Photo of seanhoyt-dot-art

seanhoyt-dot-art

  • 288 Posts
  • 49 Reply Likes
They said it’s out of their hands.... it’s up to Adobe to implement. They can’t allocate more cores.
(Edited)
Photo of John R. Ellis

John R. Ellis, Champion

  • 3895 Posts
  • 1035 Reply Likes
While LR 8 renders exported photos in parallel, it does appear to run post-processing actions like JPEGmini serially. 

Here's a CPU graph of exporting 100 JPEGs using JPEGmini as a post-processing action:



And here's a graph of exporting the same JPEGs using the Run Any Command plugin to run the utility ExifTool to remove ICC profiles from the exported photos:



They show the same pattern -- an initial burst using 75% of all the processors (typical for the rendering phase), then a tail where the post-processing action is running the external tool, one photo at a time.

Note that the author of the Run Any Command plugin is the leading expert on LR export plugins, likely more knowledgeable than any engineers currently on the LR team.  (He designed the export/publish plugin architecture and offers many export plugins for sale.)  So it's unlikely that the JPEGmini developer did something "wrong". 

If the JPEGmini developers want forward progress on this issue, they'll likely make more progress if they engage directly with Adobe (e.g. through this forum) rather than through customer proxies.