Photoshop (regardless of version) lags only when more than 1 tab is open.

Hello,

I am having the below problem in both Photoshop 2020 (v 21.2.12) and Photoshop 2022 (v 23.4.2). I am working on a 1440p monitor with a high refresh rate.

I often need more than 1 tab open in Photoshop as part of my workflow. When I have just 1 tab open, there is no lag. However, when I have 2 or more tabs open, Photoshop lags substantially. The documents I am working on are not huge; they're only 2000 pixels by 2000 pixels or so. Sometimes, the lag will subside entirely, and I can work smoothly again, without the need to close any tabs, but this is quite rare. Sometimes, the lag will persist for a while even after closing one of the two tabs.

Here is what I have already attempted in order to solve the problem:

• Brush smoothing has been reduced to 0%.
• I have tried resetting my preferences on exit.
• I have deleted all of my custom brushes.
• I am allowing Photoshop to use 69% of my RAM. Cache Levels are at 4 and Cache tile size is 1028K.
• I have Use Graphics Processor checked.
• Under Advanced Graphics Processor Settings, I have tried having drawing mode set to both Basic and Advanced. I have Use Graphics Processor to Accelerate Computation, Use OpenCL, and 30 Bit Display all checked, but I have also tried having these all unchecked. I have Anti-Alias Guides and Paths unchecked, but I've also tried having this checked.

I suspect this lag issue might have something to do with my Edit > Color Settings, but I'm not sure what they should be.

I have an 11th Gen Intel Processor, an RTX 3090 and 64GB of RAM. When Photoshop is lagging, my CPU and RAM consumption is barely affected, so my PC is not the bottleneck here.

Can anyone offer any advice?