CD-ROM speed applies to all cd drives? (inc external?)

[zver17]

I changed the CD-ROM speed from normal to silent as it (the built-in CDRW) was a bit noisy when playing music, and noticed the speed of an external DVD-RW also seemed to decrease, leading to longer burn times. Is this CD-ROM speed setting universal, and is there any way to set it differently for different drives? thanks in advance.