Can IDE Master and Slave be in different modes?

[Noriaki]

My DVD Rom can run in DMA mode 2 (UDMA/33) and it secondary slave, the secondary master is a CDRom that can only run in PIO mode 4, will that force the DVDRom down to PIO4 as well or can they run in different modes on the same channel?

Same question for hard drives, Prim. Master is a DMA4 (UDMA/66) drive, Prim. Slave is a DMA2 drive, will the slave pull the master down to mode 2 ?

 

[Madcowz]

Depends on your motherboard, but most of the newer one's should be able to set each IDE component separately. I can do that with my CUSL2

 

[Ben]

I've heard that each device will communicate as fast as it can regardless of what's on the same cable. The only drawback is that the motherboard must change it's communication type for each device if there are dissimilar protocols on the same cable. In other words, it uses DMA 2 to talk to the DVDRom, then it has to switch to PIO4 for the other CDRom, then back again. So on and so forth.

So, in theory if you had two devices that you consistently used simultaneously, it would be better to put them on separate IDE channels to reduce the amount of protocol swapping the controller had to do.

With today's quick data transfers however, you'd have a though time verifying any kind of performance increase. Everything is fast enough that no matter how you group the drives you'll be fine.

 

[Rand]

It depends on the OS and motherboard in use but and even remotely modern motherboard and OS will be able to do it with no problem.