I have the Yamaha 16x10x40 and most of the time it will only burn at either 4 or 8 and the rest of the time it will error out also. I am extremely upset. My old burner which was a 4x, burned alot better than this 300.00 yamaha that dont work right. I also have a AMD thunderbird 1.1 gighert processor, adbit kt7 raid with the newest bios update, 384 megs p133 ram, and a defragged hard drive. The newest EZ cd Creator software also and CRWIN Software. I also have the firmware updates for the yamaha drive. I think Yamaha totally messed up on this drive!