Rust DX9. Huge problem after last update.

[whood]

[video=youtube;zt10jFU-g1c]http://www.youtube.com/watch?v=zt10jFU-g1c[/video]
When i run Rust on dx9 "System" process loading CPU up to 20%. Game freezing every single second because of it. Directx 11 is just fine but with lower fps.
Idk why it even runs on my GTX260 card with no dx11 support :)
Potato specs: Pentium G860, GTX260 55nm, 8gb DDR3 1333, Gigabyte Z68XP-UD3P, Asus Xonar DS.
Is it just me or anybody else? How do i fix it?

p.s. I have 50-75 fps on dx9 with my settings so go away with your "You need to upgrade your potato". I've found a problem and reported it, that's all.