General question on installing two hard drives

[catback]

Hi,

I have two 7200 rpm, ATA100 drives and a DVD drive. I perform a lot of video editing and processing between the two drives so there is a lot of transfer of large amounts of data between them.

I'm not sure whether both drives should be on the same cable as primary master and slave or on separate cables. If separate cables, should the DVD or the second drive be set to secondary master?

I was told I would get better transfer rates with the drives on separate cables since read/write operations could be made to both simultaneously. However, i was also told that a DVD drive and a hard drive on the same cable would degrade the performance of the drive.

Can somone offer suggestions to how I should configue these three drives given the type of work i will be using them for? Thanks.

[TRILIGHT]

Definitely have each hard drive as a master on seperate channels. Set the DVD drive as a slave off of the secondary channel. Having the DVD drive on the secondary channel at least allows your system drive on the primary to operate unhindered. You should not notice a significant degradation in drive performance on the other unless you attempt to use the DVD drive at the same time. Since you say you do video editing, I'm sure you're aware you probably shouldn't be doing anything else with the system during capture anyway.

[sumptor]

Originally posted by TRILIGHT
Definitely have each hard drive as a master on seperate channels. Set the DVD drive as a slave off of the secondary channel. Having the DVD drive on the secondary channel at least allows your system drive on the primary to operate unhindered. You should not notice a significant degradation in drive performance on the other unless you attempt to use the DVD drive at the same time. Since you say you do video editing, I'm sure you're aware you probably shouldn't be doing anything else with the system during capture anyway.


The following was a response to a similar post on another board. It confuses me after reading your reply above.


"In general you're not supposed to mix optical (ATAPI) devices with IDE devices on one channel. Since the ATAPI command protocol is different from IDE command protocol, you are likely to confuse one or both devices with that kind of setup.

Also, generally, optical devices are orders of magnitude slower than regular hard drives. Any time you issue a command to the optical drive, your hard drive will be inaccessible for an extremely long time.

Finally, a lot of optical drives only support PIO modes, and you cannot mix PIO and DMA on a single channel. So this setup would drop your hard drive into PIO mode as well, again losing performance.

For a system with 2 channels, 2 hard drives, a CD-RW and a DVD-R I would set this up:

Primary: HD master, HD slave
Secondary: CD-RW master, DVD-R slave"

[TRILIGHT]

They are partially correct. However, they don't fully understand the terminology and/or overall technology at work. IDE and ATA are essentially the same thing. "IDE" or Integrated Drive Electronics is the precursor to ATA (Advanced Technology Attachment or AT Attachment) drives. I believe the "ATA" terminology came about since (I think) Western Digital owned "IDE" as a registered trademark. "ATA" is the official standard of what most people refer to as "IDE".

ATAPI (ATA Packet Interface) is a command protocol extension for the ATA interface so as to allow CDROM and tape drives to run on an ATA interface. (Does anyone rememeber the old days when you had to run a CDROM from a sound card and a tape drive from a special tape card?) At any rate, you will not confuse a system by having a CDROM drive and a hard drive on the same channel. It's true that hard drive will have slowed access but only if you're running the connected ATAPI device at the same time. As I mentioned, you normally won't be anyway. I said to put it on the secondary so that if you do run it, you will not be hindering the main system drive with the OS from performing it's function at a fast speed.

The thing they DID have entirely right is that you cannot run a PIO device and a DMA device on the same bus. The entire bus (either primary or secondary IDE channels) must run at one or the other. That being said, good luck on finding a device that only runs as PIO! The entire specification is practically obsolete with the advent of ATAPI devices. Any new IDE/ATA device you purchase now WILL support DMA. There is no reason to run the bus in the crippled PIO mode.

"Catback" said they had two drives and a DVD drive. Since they are doing video editing, they need to have each drive on a seperate channel so as not to introduce dropped frames because of bus access delays. In this setup, each hard drive should be a master on each channel with the DVD drive as the slave on the secondary channel.