bump (apologies if bumping is not allowed)

Someone must have some idea.

Descent and Duke3D have ports so you are better off using those.

Games with static screens should run fine.

Any 3D games would probably be slow at 640x+ if so then drop to a lower resolution.

No one can give you definte answers since most people on these forums that use DOSBox run them on laptops\desktops with normal processors.

Use dos32a when you can (replaces most dos extenders by a much faster one).
Notice that there are many games that use these extenders but don't advertise the fact - except maybe when run there is something saying dos4gw or something - the extender is embedded in the exe of the game, you can replace it anyway.

Games where this helps: any complex late dos game that didn't do it's own extender, typically had one of the standard ones: azrael's tear for instance. Many others.

I guess I'm repeating myself, but: recompile DOSBox with Visual C++ 2010 (Express or not) and full optimizations.