LrC serious lag since update

[Ms. Melissa Matheney]

Hi, I updated my LrC to the newest version, and since then it's been nothing but a headache. Every tool I use has a serious lag and glitch to it. I reached out to a friend asking if theirs was having issues too, to determine if it was something on my end, she said since updating hers is having the same problems. Is there anything I can do to help my LrC "catch up" faster to the work I'm trying to do? 

Or is this just a bug fix I have to wait to be fixed? Thanks. 

[dj_paige]

Are you talking about Develop tools? Or Library tools? Or something else? All of these? None of these?

[GoldingD]

Please post your System Information as Lightroom Classic (LrC) reports it. In LrC click on Help, then System Info, then Copy. Paste that information into a reply. Please present all information from first line down to and including Plug-in Info. Info after Plug-in info can be cut as that is just so much dead space to us non-Techs.

[JCVPhotography]

Hi.
I have just now come off an almost 2 hour session with an Adobe Tech to resolve SERIOUS lag issues with the latest updates - meaning from LRC 11 and this new one, 12, which slowed the program down again! It took me THREE 12 hour days to edit 350 images last week due to how soul-killingly slow the program was. 

Today, the tech literally tore down my entire adobe system, deleted all Adobe products and Creative Cloud, and rebuilt it ground up. Verified all my technical stuff, including my graphics card and that the drivers are up to date. With the graphics card, they changed the performance to "for graphics" from the general balanced setting (this will be different terminology for various graphics cards). 
I was having such immense lag... So, I exported the images I was working on (77 RAW images) to a clean, fresh, totally empty 4TB internal drive. Zero change in lag. Increased my virtual memory to the max for the amount of RAM I have (16MB). Zero change. 

Y'know what is is? I use two monitors in an extended display. The latest updates - 11 and 12 - cannot cope with two monitors, due to the draw on GPU power. HOW NUTS IS THAT. I'm dead serious. I have now set my system to display only on one monitor and have shut the other one off, and after all this song and dance, and eight weeks trying to figure this out, voila. Very minor lag.
Adobe should really, really make it a known issue that one MUST have the best graphics card they can afford, and they should use a single monitor, not two in an extended display. 

[GoldingD]

Good to know.

Now I am about to step into the OP, issue, but an inquiry that might be important.

Is your computer a desktop or a laptop, WINOS or MACOS, and in the case of WINOS desktop, does your GPU card have additional power supplied via 5v connections, or only off the slot?

For the OP, does 2 displays apply to your isue/

[JCVPhotography]

UPDATE. In fact, disabling one monitor made a difference for about 10 minutes.. So no. not the problem. Closing any other program makes no difference either. 
Win 11, 64bit desktop. GPU installed in the slot only. No additional power and I'm not sure if it can have. If you have any more info about this, I'm all ears/eyes.