Hi, Rudolf, please explain to us, and to me once again because I didn't quite understood from the emails we've exchanged. Gabe if you know something too, please share. What is/means engine synchronization? Here's what I've found in a BeNewsletter: "Much More Parallel Some people with old S3 and Cirrus Logic video cards experienced hard system freezes with earlier versions of the R4 beta. These freezes prove that the incredibly buff new R4 graphics driver architecture (designed and implemented by our own Trey "Ball-Buster" Boudreau) is working correctly -- too well, in the case of these cards. Prior to R4, the locking done when a view was drawing was coarse-grained; no two threads could draw to the frame buffer at the same time. In R4, any number of threads can draw to the frame buffer simultaneously. The only resource locked for exclusive access is the acceleration engine, and that is locked only for the time required to feed the rendering commands through the FIFO; synchronizing with the engine is intelligent and is done only when absolutely necessary. This will be of particular use in R5, when we plan to start accelerating many more calls than we do now. For R4, this means that the graphics system should be far more scalable when using cards that support the new driver model. " Thanks, Adi.