2 high speed optical drives on same IDE cable?

I remember a long time ago when copying a CD, nero had informed me that if I place 2 optical drives rated faster than 8x on the same IDE cable, my direct copy performance will suffer. Seems reasonable, but most CD/DVD burners work at UDMA Mode 2 (33 MB/s) so is there any reason why I couldn't put 2 optical drives on the same cable, and not have any performance loss doing a drive-to-drive copy?

I don't think it's the speed that lags, it's the fact that they can't both access the same channel at the same time.

copying drive to drive still goes to the motherboard, buffers into the ram, then back to the other drive. unfortunate, but true. this means twice the lag between a chunk of data being read and written, and will reduce performance considerably. at least in theorey.

So even putting them on seperate channels will only be a small increase, right? If it still has to buffer to the ram then to the other drive.

The only benefit would be that while it buffers new data into the ram it could write the older data out to the drive.

This is a great questions as I soon plan on adding a DVD burner, video capture card and dual 300GB hard drives. I will have to share channels.

i would think it would be a huge difference, because while the burner is burning the first chunk the reader could be reading the third, while the second is in ram...

and then when the burner is burning the second chunk the ram would have the third ready and buffering the fourth, which is being read.

course, a good old fashioned test would be the best way to tell