Lightroom Classic: Why not totally multi-threaded?

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Hello, my question is consecutive of my MacPro ("aluminium" version) upgrading.

My MP processor was Xeon 2,8ghz QuadCore (so height virtual cores) and I can say export of book (pdf) or photos import used it "full power".

After upgrade, my MP proc is now Xeon 3,46ghz HexaCore (so twelve virtual cores). And surprise! The two operations use only the six "real" cores. Import is followed by indexation and creation of previews, which use "all" cores. So no problem about the Xeon...

Even if performances are clearly better, I don't understand why Lightroom don't use entire power of the new processor yet. I reinstalled MacOS HighSierra and tried again, with same results.

Thx by advance,
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Posted 1 year ago

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Photo of John R. Ellis

John R. Ellis, Champion

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Please post the first ten lines from the menu command Help > System Info to verify which version you have.

A quick first thing to check: Make sure Preferences > Performance Generate Previews In Parallel is checked.
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Hello, here are system info 

Version Lightroom Classic: 8.1 [ 1200465 ]Licence: Creative Cloud
Paramètre de langue: fr-FR
Système d'exploitation : Mac OS 10
Version : 10.13.6 [17G4015]                          <= MacOS High Sierra
Architecture de l'application : x64
Nombre de processeurs logiques: 12            <= All procs are detected!
Vitesse du processeur : 3,4 Ghz
Mémoire intégrée : 16 384,0 Mo
Mémoire réelle disponible pour Lightroom : 16 384,0 Mo
Mémoire réelle utilisée par Lightroom : 1 057,3 Mo (6,4%)
Mémoire virtuelle utilisée par Lightroom : 2 613,1 Mo
Taille de la mémoire cache : 46,9Mo
Version interne de Camera Raw: 11.1 [ 112 ]
Nombre maximal de liens utilisé par Camera Raw  : 5
Optimisation SIMD de Camera Raw : SSE2
Mémoire virtuelle de Camera Raw: 329Mo / 8191Mo (4%)
Mémoire réelle de Camera Raw: 331Mo / 16384Mo (2%)
Affichages : 1) 1920x1080

And yes, generation of previews in parallel is checked. As I say, all processors work for that (both 6 "real" and 6 "virtual" in the same time). The 6 virtual are not used during import of photos from SD card, or exporting an album to PDF file.