Hi pendean, thanks for the feedback. Drawings around 5 or 10MB are no problem. At 20MB, the crosshairs start to get a little jerky. At 30MB, the quick measure command is unusable. I can easily escape out of the command and go back to normal, but until then, on bigger drawings with a lot of details, the crosshairs and quick measure don't even appear.
This is a clean install on a brand new computer, although it is a laptop, but that's why I use LT. It has a 9th gen intel i7-9850H 2.6GHz cpu, 16MB of RAM, a 1TB SSD, and an Nvidia Quadro T2000 graphics card (along with the integrated intel graphics). I will go through some settings to see if there is anything obvious, I suspect ACAD is using the integrated intel graphics and not the Nvidia graphics. Quick measure doesn't really offer enough (or any) improved functionality for me to wrestle with this for too long, so I will probably just continue never using it, but if it is an indicator that ACAD is not optimizing the available resources, it might be worth some investigation.
Dana