[Filmo]

Sorry if this is an obvious questions, but is is possible to attach multiple external DVD burners/readers and have them all do distinct operations?

For example, with 3 externals, could we copy files from two of them to a local disc while simultaneously burning to the third one???

If possible, is there a practical limit to the number of drives we can have reading data off discs to the local machine?

Our clients often send us DVDs of audio or video media which we have to convert to MP4 or MP3 prior to putting it on our servers for them and doing it one disc at a time is a drag.

Sorry if this seems like an obvious question.

[jmiddel]

Yes, in fact Toast 11 can burn stuff to 3 opticals at the same time. If you are doing different operations from the same software to multiple disks, you may need more than one copy of the SW. Prior to Toast 11, I'd burn stuff to 2 externals using Toast 8 and DragonBurn running simultaneously. The limit is probably determined by RAM and CPU.

[Filmo]

Thanks for the info regarding Toast.

We're most interested in read/rip capabilities in particular. For example, we often use Cinematize Pro to rip videos off a disc. Aside from RAM and CPU (4GB on an i5), will USB bus contention play much of a factor? Any ideas on the practical limits of how many read drives can be attached. My thoughts would be 1 per core as a practical matter.

I'm not even sure multiple instances of Cinematize Pro can be launched, but if not, what software would you recommend for doing simultaneous rips? (1 rip per core)

[reader50]

Multiple instances are easy if you have Fast User Switching active. Jump accounts, and fire up a 2nd copy of your application. I've done this when I want to defrag multiple HDs simultaneously.

As for bus congestion, plug devices into different ports on the computer. Each port is often on it's own bus; after plugging burners in you can check via Apple System Profiler. Confirm they're each on their own bus.

Even one optical device per core may be overkill. The CPUs and (to a lesser extent RAM) have gotten so much faster than drive access that Apple found it worthwhile to compress applications on drives. They actually saved time reading in the smaller compressed file then uncompressing, rather than load a bigger file. That's with hard drives. Optical drives are *slow* by today's processor standards.