okay..3 sams in a row...now thats kinda weird 😀
most severs only let you go to bout directx 7 at the lowest
IMHO , your video memory sounds like it is shared
Are you by any chance using intel GMA graphic cards?
If yes , those graphic cards are a underpowered when it comes to running hl2 mod games...
Naturally it would work better in bootcamp due to the native window drivers
Since Crossover is a implementation of the windows api , naturally things might slightly slower than the expected speed
Lowering direct x level would help quite a fair bit ....
If you are not using the intel graphic card , pls do tell