Thing is every througput is usually done via the ide or scsi bus.
And that’s going to be more the limit than the writing speed.
If you copy on the fly , you could have the danger that you got a buffer underrun , just because there was some scratch on the source cd and it had to correct itself for 10 million times before correctly reading it. In the meantime the buffer empties.
But nowadays with the bufferunderrun protections , who cares ? The writer will wait.
You could hook up a Plextor 40 speed writer on a 386 with 5 megs of ram (minimal for windows 95) and start writing. It’ll work.
I doubt that it’s ever gonna reach the 40 speed writing though. The bus isn’t just that good.
I have a Pentium 1 233 MMX , overclocked to 266 (by the core , not the multiplier) and my 12 speed ide plextor burner writes perfect.