glMultiDrawArraysIndirect and CPU overhead (software emulation in AMD drivers ??)

Hi,

     I'm having strange results using glMultiDrawArraysIndirect : the CPU usage is really really high for such a function (around 60% CPU core), and increase with the number of primitive to draw (not the number of polygon drawned).

I tested it on an NVidia card with nearly 0% CPU usage for the same call (a low performance one, far less than the Radeon HD7770 I'm using, so not GPU limited, less than 15% usage on AMD GPU).

I'm running it on 64 bits linux with last drivers. Seems like this function is emulated in software.

  Can anyone confirm it ?

       Thanks,

               Christophe