I have updated to 1.3 and set the weapon debris effect to ultra (and others) but I cant see the effect in game.

I googled a while and tried a few methods but none worked (including set physX into GPU)

I have gtx970 and 2500k cpu.

Is there any step I missed or is it because my card doesn't support flex?

I have 980 and it works - tried it by shooting a random wall. There were pieces lying around, so I tried it out with grenade and it splat all over the place with no FPS drop at all.

Cool effect.

I think you need to have HBAO enabled in the launcher.

I dont see any piece only the bullet case

I already tried enable HBAO, not work. thanks anyway