Light Room running very slow

The only thing you need to know is this - don't take advice from anyone on how to 'improve' performance. The simple fact is this - Adobe has no idea how to make their software work with hardware. period. It doesn't matter if you use the absolute latest and most advanced hardware, Lightroom Classic CC is and will forever be a horrendously performing application. Until Adobe master the BASICS, they will never get it. Years and years of using their software, performance has always been the big issue with their software. PC or Mac. If you've ever wondered why there is so many alternative applications like lightroom, it's because people are fed up with Adobe giving zero-craps about performance. I have no faith they will ever master these fundamental problems with their software.

Photoshop has a much simpler job to do than Lightroom. It just has a simple matrix of pixels to move around. Lightroom has to do the raw data demosaic and the lens corrections, cloning/healing, brushes etc in a nondestructive manner, so every change it has to recalculate the entire chain. In photoshop, your edits are 'baked-in" so it doesn't have to go through the entire chain of calculations every time.

Starting to get similar issues (reply's) mixed up. Might have shared this.

Three links that relate:

Lightroom Quick Tips - Episode 92: Optimize Lightroom Performance - YouTube

https://f16.click/tips/lightroom-performance-tips.html

https://digital-photography-school.com/10-tips-to-improve-lightrooms-speed-and-performance-without-additional-hardware/

I had the same problem and I think (touch wood) that it might be solved.  I have an extremely high spec PC with 32gig of RAM but LR Classic had become unusable - literally.  I'm a pro photographer dependent on LR Classic and it was very worrying for me.

Based on davidg36166309's post, I compared my system to his (pasted system info into Notepad etc) and I noticed that my Lightroom Camera Raw Memory cache size was only 8.9MB whereas his is 45.5MB so I altered mine to 50MB which appears to have done the trick. (From Library module.... Edit / Preferences / Performance: Camera Raw Cache Settings.    I've kept the cache on my C drive which is a small 256GB but fast M.2 SSD.

Incidentally, my "Camera Raw virtual memory shows 1184MB / 16334MB (7%)" and "Camera Raw real memory: 1332MB / 32668MB (4%)", but I don't know how to increase these or if it is an automatic setting.

I have no idea why increasing the Camera Raw Memory cache seems to have worked because 50MB still seems like a very small amount compared to my 32 gig of RAM and dedicated Photoshop cache on a 3TB WD Black internal drive !!

Anyway, if it turns out that I've counted my chickens before they've hatched I'll post an update here on this thread.  Also, I'd be very interested to hear if it works for anyone else, so please post if it does.

Did the service Nerds (techs) consider if your computer, or some component in it is overheating? Does this PC have a temp sensor installed that is displaying CPU and cabinet temps?

OTHER MEMBERS, any recommendation for a app to monitor the O.P. PC temp?

I say this, because after some time goes by your app goes buggy, Overtempt reaction??

To determine your LightRoom (LR) version and architecture, In LR click on Help (menu bar) then System Info, a screen will pop up.

Click on the Copy button.

Bring up Notepad, or some other text editor, and paste that info. Delete most of the info from this test file.I have pasted my example below. Providing this info on this forum is helpfull for diagnostics by other members

(you could just take a screen shot, but that might give info you do not want out like e-mail address)

You will see if you are running x64 app

For example (with emphasis added)

(not the O.P. data)

(Windows PC, apple I don't know)

Lightroom Classic version: 8.0 [ 1193777 ]

License: Creative Cloud

Language setting: en

Operating system: Windows 10 - Business Edition

Version: 10.0.17134

Application architecture: x64   (Yep x64)

System architecture: x64

Logical processor count: 8

Processor speed: 4.0 GHz

Built-in memory: 16317.1 MB

Real memory available to Lightroom: 16317.1 MB

Real memory used by Lightroom: 6438.2 MB (39.4%)

Virtual memory used by Lightroom: 10123.7 MB

GDI objects count: 1211

USER objects count: 3348

Process handles count: 3442

Memory cache size: 46.5MB

Internal Camera Raw revision: 61

Maximum thread count used by Camera Raw: 5

Camera Raw SIMD optimization: SSE2,AVX,AVX2

Camera Raw virtual memory: 1670MB / 8158MB (20%)

Camera Raw real memory: 1683MB / 16317MB (10%)

System DPI setting: 96 DPI

Desktop composition enabled: Yes

Displays: 1) 1920x1080

Input types: Multitouch: No, Integrated touch: No, Integrated pen: Yes, External touch: No, External pen: Yes, Keyboard: No

Graphics Processor Info:

DirectX: NVIDIA GeForce GTX 980 Ti (23.21.13.8813)   (oh, what is your GPU? is it a problematic one, we would see here, mine works just fine)

Application folder: C:\Program Files\Adobe\Adobe Lightroom Classic CC   (yep, again, x64 program folder)

Library Path: W:\Active Projects\Photography\3 Vacation October 2010\3 Vacation October 2010-2-2-2-2.lrcat

Settings Folder: C:\Users\goldi\AppData\Roaming\Adobe\Lightroom

Try disabling your anti virus program and test.