[GEM-dev] Frame rate on MacOsX

[Jack]

Hello,

I am working on an installation on MacOsX.6.7 with Pd-extended 0.42.5 
and Gem 0.92.3 (compiled Sep 22 2010).
The graphic card is a ATI Radeon HD 5770.
On this environment, i can't get a stable frame rate. With [gemwin 50], 
i get sometimes with the abstraction [realFPS] : 60 fps (strange no ?) 
then 5 seconds after 40 fps. Even when the scene is the same.
How can i obtain 60 fps when it is write [gemhead 50] ?
Someone has a similar problem ?
How can I fix it ?
Thanx.
++

Jack