question about drive clocks

[bockchow]

ok i was talking to a freind about burning from cd to cd instead of haveing to copy it to the drive and then to the cd. i told him he should put the optical drives on different channels to speed up the process he said

him:if you put a slower accessing optical drive on the same bus as your hdd you'll lose ata-100
bockchow: no you don't, maybe back in the day but thats changed
him: yea you will, because it operates on a single clock, a slower drive can't step up, so the faster drive has to step down, that's why it's always best to put optical drives on the secondary controller,or buy a pci controller

is that true?

 

[mikecel79]

I don't believe you can have two different devices with different UDMA modes and have them run at the highest speed. For example you if you have a UDMA 2 and UDMA 4 device on a single IDE channel it forces it to run at UDMA 2. At least this is how it is on my BX board. I'm not sure if they changed this in the later revisions.

There is another reason to keep your two optical drives on seperate channels. An IDE controller can only access one device on a channel at a time. So you should seperate your optical drives to different channels.

 

[LED]

bockchow you are correct as todays chipset can identify the devices seperately and the OS will take what's available automatically...No one is going to tell me that my ATA 100 device is running @ ATA33 because my DVD Optical is behind it...just do benches and you'll see.
As far as copying on the fly seperate IDE channels for Optical devices is prefered for speed...