I'm having trouble getting Rootsmagic to work properly even in Crossover on Ubuntu 18.04, so I tried it in 64 bit Windows 7 home in VirtualBox. It slowed to a crawl. Making sure MSXML6, flash, Internet Explorer, and Net Frame or whatever it's called were installed helped a little. Expanding resources like RAM and processor cores did not help at all.
In Crossover Rootsmagic is almost normal but still a little slow.
Then I tried 32 bit Windows 7 Professional, and Rootsmagic works almost normally.
On the same 64 bit computer in Windows 7 Home it worked perfectly.
I think that Rootsmagic is struggling to run in 64 bit operating systems. The extras you have to add to make it run are intensive graphics stuff that genealogical software with a GUI interface that uses XML should hardly need to run. Since even diehard users of old equipment like me are no longer using 32 bit computers, it's hard to imagine why Rootsmagic does not update. It's hard to believe they're trying very hard to do much of anything. They seem to be a small group of elderly people.
I am currently running RM7 under Wine on Linux. It works well.
I also have an installation in a Windows 7 Home 64 bit virtual machine running under Virtualbox (on the same computer) and RM is at least as fast there.
Having said that, the Windows virtual machine has its own SSD dedicated to it. I expect that RM is I/O bound (waiting for data from the database) rather than compute bound and so anything you can do to speed up data access would help.