Is it okay to slave a DVD drive on the same IDE cable as a hard drive?

[Ken90630]

Hey, All,

A friend of mine has a 5-year-old Foxconn motherboard with a couple leaky caps, so I'm going to get her a new board.

This PC (a clone) has one IDE hard drive and one IDE DVD-RW drive, both connected to their own dedicated connectors on the mobo. Prob is I can't seem to find an Asus, Gigabyte or Intel board (my brand preferences) with more than one IDE connector.

That being the case , would there be any problem with hooking the HD directly to the mobo's IDE connector and slaving the DVD drive on the same cable? I seem to remember reading somewhere, awhile back, that that wasn't the greatest idea but I can't remember why. What probs could/would arise?

I'm trying to keep this fix as inexpensive as possible, so replacing the DVD drive with a new SATA one is not a great option.

Any advice would be appreciated.

 

[California Roll]

It should work fine. The only drawback being that the slower DVD drive (ATA-33?) will drag down the speed of the HD (ATA-100?) down to the same level (ATA-33?).

 

[Ken90630]

Are you sure? I don't think that would happen.

 

[Billb2]

Originally posted by: California Roll
...the slower DVD drive (ATA-33?) will drag down the speed of the HD (ATA-100?) down to the same level (ATA-33?).

No way. The drives will read/write at whatever speed they are designed for.


The issue is that when copying from drive to drive, the IDE buss has to handle the reads from one drive and the writes to the other at the same time. You can copy/burn faster with the drives on separate IDE channels. But, unless you GF is a fanatic about copy/burn speeds, she won't notice anything with the drives on a single channel.

 

[Golgatha]

Originally posted by: Billb2

Originally posted by: California Roll
...the slower DVD drive (ATA-33?) will drag down the speed of the HD (ATA-100?) down to the same level (ATA-33?).

No way. The drives will read/write at whatever speed they are designed for.


The issue is that when copying from drive to drive, the IDE buss has to handle the reads from one drive and the writes to the other at the same time. You can copy/burn faster with the drives on separate IDE channels. But, unless you GF is a fanatic about copy/burn speeds, she won't notice anything with the drives on a single channel.

Wrong, the transfer rate is slowed down to the slowest spec on the channel, so the ATA100 drive will operate at ATA33 speeds. Depending on the drive, this could very negatively affect system performance. I'd personally spend the $20-$25 on a SATA optical drive to remedy this situation.

 

[Golgatha]

Originally posted by: Golgatha

Originally posted by: Billb2

Originally posted by: California Roll
...the slower DVD drive (ATA-33?) will drag down the speed of the HD (ATA-100?) down to the same level (ATA-33?).

No way. The drives will read/write at whatever speed they are designed for.


The issue is that when copying from drive to drive, the IDE buss has to handle the reads from one drive and the writes to the other at the same time. You can copy/burn faster with the drives on separate IDE channels. But, unless you GF is a fanatic about copy/burn speeds, she won't notice anything with the drives on a single channel.

Wrong, the transfer rate is slowed down to the slowest spec on the channel, so the ATA100 drive will operate at ATA33 speeds. Depending on the drive, this could very negatively affect system performance. I'd personally spend the $20-$25 on a SATA optical drive to remedy this situation.

Well I'll be embarrassed!

http://en.wikipedia.org/wiki/A...ple_devices_on_a_cable

It seems I'm wrong and you'll be fine with both devices on a single ATA cable. Just be sure to use an 80pin one.

"Lowest speed"

It is a common misconception that, if two devices of different speed capabilities are on the same cable, both devices' data transfers will be constrained to the speed of the slower device.

For all modern ATA host adapters this is not true, as modern ATA host adapters support independent device timing. This allows each device on the cable to transfer data at its own best speed. Even with older adapters without independent timing, this effect only applies to the data transfer phase of a read or write operation. This is usually the shortest part of a complete read or write operation.

 

[tcsenter]

Originally posted by: Golgatha
Wrong, the transfer rate is slowed down to the slowest spec on the channel, so the ATA100 drive will operate at ATA33 speeds.

Was true about 12 years ago, hasn't been true for about 10 years.

 

[Ken90630]

And the winner is: Billb2! :laugh: :beer:

But thanks to all who replied (and to Golgatha for the correction). I've never been sure about this issue, and it's never really mattered 'cuz I've always had boards with at least 2 IDE connectors. But those are becoming scarce. Like Golgatha said, of course, an inexpensive SATA drive is an easy solution if the user still wants separate cables/connectors for each drive.

Now I'm wondering: If the HD and DVD drive (both IDE) are put on the same cable, with the DVD drive as the slave, will that affect the boot device order options in the BIOS? Will it still be possible to set the DVD drive as the first boot device if it's slaved on the HD's cable? I don't think I've ever set a slaved drive to be the first boot device before.

 

[LokutusofBorg]

The SATA optical drives are only $20. I know you said you wanted to keep it as cheap as possible, but that's just dirt cheap.

Anyway, the performance issues and drawbacks have already been answered, and there aren't really any other than bandwidth when talking DVD <-> HD. (The practical implication here that even casual users might care about is installing software off of DVD/CD will be slower with them on the same channel.)

I had a DVD-ROM and a DVD-RW on the same IDE cable, and could boot from either of them, to answer your last question there.

 

[Golgatha]

Originally posted by: Ken90630
And the winner is: Billb2! :laugh: :beer:

But thanks to all who replied (and to Golgatha for the correction). I've never been sure about this issue, and it's never really mattered 'cuz I've always had boards with at least 2 IDE connectors. But those are becoming scarce. Like Golgatha said, of course, an inexpensive SATA drive is an easy solution if the user still wants separate cables/connectors for each drive.

Now I'm wondering: If the HD and DVD drive (both IDE) are put on the same cable, with the DVD drive as the slave, will that affect the boot device order options in the BIOS? Will it still be possible to set the DVD drive as the first boot device if it's slaved on the HD's cable? I don't think I've ever set a slaved drive to be the first boot device before.

No, the OS or BIOS couldn't care less whether a drive is a master or slave on the IDE channel as far as booting to the OS is concerned.

 

[xfile]

Damn....where have I been the last 10 years!

 

[Golgatha]

Here's another option for better performance.

http://www.monoprice.com/produ..._id=327&seq=1&format=2

Get yourself an IDE to SATA converter.

 

[Blain]

Originally posted by: Golgatha
Well I'll be embarrassed!

http://en.wikipedia.org/wiki/A...ple_devices_on_a_cable

Don't worry about it.
Just edit the Wikipedia information to conform to your reply. :laugh:

 

[California Roll]

Originally posted by: Golgatha

Originally posted by: Golgatha

Originally posted by: Billb2

Originally posted by: California Roll
...the slower DVD drive (ATA-33?) will drag down the speed of the HD (ATA-100?) down to the same level (ATA-33?).

No way. The drives will read/write at whatever speed they are designed for.


The issue is that when copying from drive to drive, the IDE buss has to handle the reads from one drive and the writes to the other at the same time. You can copy/burn faster with the drives on separate IDE channels. But, unless you GF is a fanatic about copy/burn speeds, she won't notice anything with the drives on a single channel.

Wrong, the transfer rate is slowed down to the slowest spec on the channel, so the ATA100 drive will operate at ATA33 speeds. Depending on the drive, this could very negatively affect system performance. I'd personally spend the $20-$25 on a SATA optical drive to remedy this situation.

Well I'll be embarrassed!

http://en.wikipedia.org/wiki/A...ple_devices_on_a_cable

It seems I'm wrong and you'll be fine with both devices on a single ATA cable. Just be sure to use an 80pin one.

"Lowest speed"

It is a common misconception that, if two devices of different speed capabilities are on the same cable, both devices' data transfers will be constrained to the speed of the slower device.

For all modern ATA host adapters this is not true, as modern ATA host adapters support independent device timing. This allows each device on the cable to transfer data at its own best speed. Even with older adapters without independent timing, this effect only applies to the data transfer phase of a read or write operation. This is usually the shortest part of a complete read or write operation.

I'm right there with you. I remember reading about this when I put together my 386/486 systems. Since then I've always kept them on separate channels and never realized this changed.

 

[taltamir]

Originally posted by: Golgatha

Originally posted by: Ken90630
And the winner is: Billb2! :laugh: :beer:

But thanks to all who replied (and to Golgatha for the correction). I've never been sure about this issue, and it's never really mattered 'cuz I've always had boards with at least 2 IDE connectors. But those are becoming scarce. Like Golgatha said, of course, an inexpensive SATA drive is an easy solution if the user still wants separate cables/connectors for each drive.

Now I'm wondering: If the HD and DVD drive (both IDE) are put on the same cable, with the DVD drive as the slave, will that affect the boot device order options in the BIOS? Will it still be possible to set the DVD drive as the first boot device if it's slaved on the HD's cable? I don't think I've ever set a slaved drive to be the first boot device before.

No, the OS or BIOS couldn't care less whether a drive is a master or slave on the IDE channel as far as booting to the OS is concerned.

in theory, a few years back I had an ECS board with a VIA chipset that did.