I forgot to write, I use simulation everytime and it can be seen from the attached log.
Code:
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09:24:21 AM #13 Phase 32 File ExtendedProgress.cpp, Line 537
Simulation started at 16x (2400 KB/s)
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09:30:20 AM #21 Phase 33 File ExtendedProgress.cpp, Line 537
Simulation completed successfully at 16x (2400 KB/s)
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I burn CDs everytime at 16x. By Brasero could be set only speed when burning images, but I think that settings should be very similar.