Lightroom lag & broken local adjustments on >4k displays

[JULIANCASSADY]

At this point, I'm so used to trouble shooting LR that nothing really surprises me, but I've got one that will really make everyone chuckle today.  For the most part, LR Classic 7.4 now runs smoothly on my MacBook Pro laptop... but is almost unusable on my absurdly priced 10 core, 128GB RAM, 3.1 GHz, Radeon Pro Vega 64 stacked iMac Pro.  I understand the limitations of the software and it's lack of multicore application, but this is frankly absurd.

The issue is this: graphics acceleration in LR is still in beta, but without it LR can't keep up with displays over 4k in resolution.  I'm glad the graphics acceleration crop bug was fixed with the recent update, but currently my options are as follows...

1. Edit on my 16GB RAM laptop with no issues.

2. Edit on the 5k iMac Pro display with graphics acceleration turned ON.  This renders the used of the adjustment brush, cloning, healing, and any local adjustments completely broken.  Initial brush strokes cause the entire system to choke for 2-3 seconds and are often not even recorded.  I edit hundreds of images a day and each of them receives a pass with a few healing spots and adjustments so this is a very big issue for me.

3.  Edit on the 5k iMac Pro display with graphics acceleration turned OFF.  This fixes the adjustment brush issue, but makes regular develop functions extremely sluggish and bloated.  Moving around within lightroom is also slow.

What gives?  I'm tired of being used as a beta tester.  If this program is built for professionals, it should run perfectly on an $8,000 machine and especially on a high resolution display.

iMac Pro

3.1 GHz Intel Xeon W

128 GB 2666 MHz DDR4

Radeon Pro Vega 64 16368 MB

5k Retina Display

[Akash Sharma]

Hi JulianCassandy,

We're sorry about the sluggish performance of Lightroom Classic CC on your iMac Pro. This issue is definitely recorded and being worked upon as it does affect the app's performance and slows down the overall workflow . I'd recommend that you add your vote and feedback to the below discussion where our Engineers are tracking this issue. This way they can interact with you and they'll also get to know more about the problem. Here's the link for the discussion: Lightroom Classic CC interface is very, very slow on iMac Pro | Photoshop Family Customer Community ​

Thanks,

Akash

[JULIANCASSADY]

3 months later and still working through an absurdly sluggish workflow day in and day out.

Is real time editing on a 4/5k monitor that difficult of a code to crack?  Odd that I can edit 4k video in realtime, full resolution, and my computer eats the footage easily, but a simple RAW photo edit slows things to a crawl.

This needs to be fixed.

[JULIANCASSADY]

8 months later and STILL worse than ever. 

This application is built to be professionally used.  I've sunk hundreds if not thousands into CC subscriptions.  This is insanity.