I'm using the newest version of RStudio (1.1.456), and have been having very bad lagging while scrolling up and down in my script. I'm using a 2 year old Dell XPS with a 1920 X 1080 display, Windows 10, and plenty of free RAM. It doesn't seem to do it (or I just don't notice it) on really small scripts, but I also do not write huge code either. usually 200-300 lines or so, and this is enough to really bog my scrolling down. My files are all read in using read.csv from a folder on my desktop.
A few noteworthy things: If I open up an existing script, the first scroll down to the bottom is painless, but then as I scroll back up it becomes bogged down. I have uninstalled and reinstalled RStudio a couple of times and it seems to get a little better right after I reinstall the program again. But it starts to get laggy shortly after running the program for a bit. Lastly, I have tried the newest daily build (ver. 1.2.1026) and the problem does not occur in this version. But the daily build doesn't seem like a long-term solution.
I appreciate any potentially helpful tips.