Hi all , 
       I run a simple test with qnx650 on beagle xm (512M ram) board . and When I try to copy a 300M file to /tmp with 
qconn via a usb network adapter ( asix chip )

I got a very interesting result . 

I dont know about qnx's memory manager . 

I want know if we use the heavy memory load , will we get the poor performance than the  lower? 
how much memory (percent ?) should we to keep free when we want to keep the better cpu performance ? 

Its not current in our project . just personal interesting . so ,give me some help if you have time .
Thanks all