question about ATA-100 devices

[pushlatency]

Hi, this question is probably rather trivial, but i can't remember for the life of me, nor remember where to go to find the answer myself.

If you have two devices on an ATA-100 capable IDE channel, one of them that supports ATA-100 (like a IBM 75GXP hard drive) and one that doesn't (like an internal zip drive, or CD-Rom). The HD is set as the master, the other device is the slave. And they are both connected to the controller using a 80 pin ATA-100 IDE cable.

Will the hard drive still be able to run at ata100 speeds? or does it have to default down to the highest speed capable of the zip drive/CD whatever. Also, if i had a set up with 4 IDE devices and an ATA-100 capable controller, which would be the best way to arrange them on the channels

IBM 75GXP HD
IDE CD writer
IDE DVD Drive
IDE Zip drive

thanks in advance

harris

 

[aa_koch]

Unfortunately, your IBM will not be able to fully utilise ATA/100. Only if two identical (both ATA/100-compatible) devices are attached to the ATA/100 controller, will you take advantage of this protocol. In your case, the IBM will suffer from the "interference" coming from your CD-ROM/CD-RW/ZIP.

I am not too sure about the setup, because I don't know which protocol (PIO4, DMA mode 2) the ZIP-drive runs. But to fully use the capabilities of your IBM drive, you should hook it up as a single drive to the ATA/100 controller. Then, unless you copy CDs from your DVD-ROM to your CD-RW directly (that is, you don't copy the files to the HD first but transfer them directly to CD-R), it would probably best if you hook up your CD-RW and DVD-ROM together on a single IDE controller, as they should both be able to run in DMA mode 2 and you'll most likely not use both of them at the same time. This leaves the ZIP-drive as a single unit, also.

On my ASUS A7V motherboard, I can hook up to four IDE devices through the regular IDE controller, while I got my IBM HD connected to the on-board Promise controller. If your motherboard doesn't have this, you might consider buying a seperate card which plugs into your PCI slot. However, I don't think that in practice, you'll notice an awful lot of difference, so it depends on how important it is to you that your drive utilises the ATA/100 protocol.