Yes I know I don't really say this for you, some user use other's 3d engine and use exemple the default mesh loader for load stuff.
It make many many mesh instances to render and don't have any special optimisation.
On this case just to render 2000 baril's it can get very low fps.
Anyway if i'm not wrong 2000 baril's from physic with good step without any visual can run at around 20 30 fps on a normal good computer with multithread.
It's only speculation I never have try about 2000 maybe it can cost a lot more.