My experiences with IDE Chaining

[Ruahrc]

I have been told that you should not pair fast (i.e. HDD) and slow (i.e. CD-ROM) drives on the same IDE Cable. The system will have to wait for the slow one, and thus the fast device always waits around.

Well I have 4 IDE Devices on 2 Chains:
Pri Master: ATA66 HDD (ATA/66)
Pri Slave: LS-120 (Mode 2)

Sec Master: 48x CD-ROM (ATA/33)
Sec Slave: 4x4x32 CDRW (Mode 4)

I did it this way because the 80-pin cable for my HDD is specific on which plugs go into the master, slave, and mobo. The only way I could work 4 devices would be the above config, due to cable length limitations, etc.

Previously, (Pre-CDRW) I had:

Pri Master: ATA/66
Pri Slave: None

Sec Master: 48x ATA/33
Sec Slave: LS-120 (Mode 2)

I don't really notice any drop in performance after re-mixing the chains. Should I be?

Just my experiences, let me know if I've lost it or....

Ruahrc

[OuTpaTienT]

I'm a little fuzzy on this too, so someone please correct me if I'm wrong...BUT...

I believe you will only incur a performance hit on your Pri Master when both the Pri Master & the slower Pri Slave are trying to operate at the same time (like copying stuff from the HD to the LS-120). Otherwise, as long as the Pri Slave remains dormant, you shouldn't see any performance loss.

That's how I understand it, but I'm not very sure of myself on this one, so let's wait and hear from others as well.

[jl123]

That's how I thought it worked too OuTpaTienT. I agree with Out. Unless both devices are being accessed at the same time I believe it shouldn't degrade performance. At least that's the way I think it is.

~Joel

[djurom]

That's the most logical solution because when only one device is working and the other is on idle state all available time goes to active device. Only when secondary device tries to use IDE channel it reserves access time for itself reducing for the amount it needs resulting in performance loss.

[Ruahrc]

Makes sense. Thanks guys, I haven't lost it after all http://sysopt.earthweb.com/forum/smile.gif.

Ruahrc

[Axel]

If you really have a need for that many storage devices - then you should look into promise technology ide adapters - a few drive hotswap bays and set up a RAID solution -

Are you just using all the junk you have laying around - or is there a need for each of these devices?

Not to sound too critical - I used to be the same way - each system I built initially has almost every spare I have laying around the office in it for no good reason other than that I have them. - Then I rip out the photoscanner I don't use - the 120MB hard drive, etc. etc.... - the only thing I haven't built back into a system is an old 5.25 floppy drive I have - "just in case" - just can't seem to bring myself to get rid of it....

perhaps I'll fine a rosetta stone buried on a 5.25 floppy...... who knows....

[Ruahrc]

Yes, I actually use all 4 devices.

HDD: duh
LS-120: This isn't a 120MB HDD it is a 120MB 3.5" floptical drive. It also reads/writes regular 1.44MB floppies so it is my floppy drive.
CD-ROM: Self Explanatory
CDRW: Ditto

I bought an A7V the other day and will put it in as soon as I can. Can I just plug each of my devices as master into each of the 4 IDE headers and have it work fine or do I need to do some config stuff?

Ruahrc