It is laggy to the extent where a normal workflow is not possible any more.
Using an 8-core AMD 3.1Ghz, with 16GB of RAM and an Nvidia GTX960 under Win10 64bit.
Switching between photos in the Develop module, even when Smart Previews have been generated. I've even changed the standard preview size to a size smaller than my 4K monitor. Happens on my Fuji XT-2, XPro2 RAW files (compressed) and Fuji jpegs. Haven't yet tested my Canon files.
Slow previews when scrolling over presets. It used to simply preview in the navigator window, but now it previews simultaneously the on-screen images at preview-size which makes everything reaaaaalllllllyyyyy slow. I don't like this feature but can't find a way to turn it off.
Pasting copied settings. Too much delay now.
I've since rolled back to 7.2 until these performance issues are resolved.
i7 4770K, 32GB RAM, Win 10 64, GTX 1070 8GB card, 4K monitor.
I got Lightroom 7.3 to make a pano from 10 vertical D800E images - this it did without too much of a sweat, and the result is a DNG at 33,300 pixels and 970Mb.
If I try to add even a graduated filter to this not-so-massive DNG then the Dev module crawls to a halt - just placing the filter takes nearly 2 minutes of spinning progress indicator.
If I close Lightroom and open the DNG in ACR, then I can apply any adjustment I like and there is no slowing down of anything.
So why would ACR act normally and the Lr7.3 dev module act like it's been shot with a very big gun??
Today it was so particularly slow for me that I had to record a video
Its so unusable at this point that I'm wondering if I should ask for a refund until they find a solution.
Sorry for the poor quality, I had to record with my phone as screen recorders wouldn't work with lightroom sucking up all computer resources.
I also did the re-install and made new smaller catalogs and all sorts of other little adjustments including the 7.4 update with no real improvement. My system is a new, fast iMac with 32gb ram and a SSD, which apparently well exceeds the minimum spec.
In my experience LR gets a bit erratic; sometimes takes 90 secs to change from Develop to Library module, if the program has been in the background. Showing/hiding masks may not work at all when clicking on edit pins and can take up to 90-100 seconds when selecting the checkbox. The brush lags so much that painting layers of adjustment is not functional.
It's become so frustrating I'm exploring migrating to other platforms to ease the pain!
All very frustrating for a program that I use constantly and love enormously (when it works well!)
I noticed that on my side disabling GPU support made things less laborious.
(Moreover, advanced tests have allowed me to see that the GPU was never solicited apart from the use of brushes, while slowing down everything else - usage advantage almost to zero all along)
Without the GPU it is more livable but, even downgrading the version of lightroom to the last but one can not reprofit with a proper speed thanks to the CPU + GPU
Please correct this defect, I spend hours on my photos ...
* Another problem appeared with the last 2 versions:
Full screen display bug on OSX latest version + iMac 5K.
as soon as we switch to another "desktop" or that we click elsewhere than in LR are display takes odd proportion until it becomes normal after a click in the app.
Courage and thank you to the develloppers for their work to make LR always more functional and powerful (a preference for me for the overall fluidity of the application, do not hesitate to load my GPU there is margin! ;))