Question about destruction

I’m trying use PhysX3.2 to simulate simple destruction.
The debris was exported from Max.The shape use boxshape simply.But as the shape is not precisely,the debris shape often overlap with each other at the first time.If a small box overlaped with a large box, the smaller one will create a large speed,it looks not comfortable.Maybe because some debrises are part under terrain at first time, i don’t sure which results this appearance.
Is there any way to solve this question? Or could I set a max linear speed?
Thank you very much!

Sorry,It look like because models are scaled larger.
But the movement looks much different from scale 1.0.
Is there any other properties should scale except the shape size?

This sounds strange because it runs well on my side. Can you send me your sample? My email is

Sorry,it’s my stupid fault.The initialize position not scaled…