Having two burners on the same IDE channel will likely produce two coasters (I/O flow problems), and even if it works it will take more time than burning them separately. Use separate IDE channels for your burners. And you can afford this with Nero to burn the same data compilation or image, while other programs (Discjuggler, RecordNowMax) can burn at the same time two different things at two burners at the same time without problems (actually more, with the right program licence). Never at the same IDE channel, though. You can have more than one burning device only on SCSI buses, which have their won special disconnect feature- unless you can afford a pile of frisbees at the end of your burning session.