RenderTexture update simultaneously on different threads

Hey *,

I want to update several RenderTextures (rtt) in my programm (C# using mogre) on different threads in parallel.
Each thread has its own RenderTexture and the scene is not changed at all.

Currently I'm using semaphores to secure the updating process, but this procedure is reaaally slow. Maybe you have an idea how to speed this up?
Is there another function to update a RenderTexture?


mogreLock.WaitOne();
rttSVF.Update();
mogreLock.Release();


- Have a nice day!
Marcel