'Master' and 'Slave' drives

[ManOfSteel]

Hello,
I would like to know what does it mean to put a drive (HDD, CD, ...) as master or slave. What's the technical difference(s) between the two? I once tried to put an HDD and a CD/R/Rw both as master and the computer began to run very slowly, why?
Thanks for your help.

[I Lostalim]

In the basic sense it's for determining which should get priority.

Typically what you have on each cable is one Master device and one Slave device (depending on which of the two plugs you use). It is also determined by the positions of a particular "jumper" on the hardware itself - most major companies label all the jumpers and plug slots on thier hardware so it shouldn't be too hard to find.

Generally if you're trying to run a HDD and a CD drive off the same IDE cable, then it's best to use the HDD as Master and the CD as slave.

[Solar]

And if all you have is said HDD and CD, you're yet better off to run each as Master on a seperate cable to maximize performance.

Position (first or second port) on the cable has no influence to the Master / Slave setting; that is only determined by the jumpers. Signal quality, however, is better at the end of the cable (reflections).

Really old HDD might have an additional "Single" setting if run as only device on the cable.

[mystran]

Hmmh. Does "cable select" work based on the connectors on the cable, or signal quality?

[I Lostalim]

Position (first or second port) on the cable has no influence to the Master / Slave setting; that is only determined by the jumpers. Signal quality, however, is better at the end of the cable (reflections).

Uh - yeah, I think I was speaking in shorthand ....in my defence: It was late, I was tired

[Solar]

Hmmh. Does "cable select" work based on the connectors on the cable, or signal quality?

Neither. "Cable select" requires a special kind of cable where one pin is not connected to the second connector, only to the first. Those special cables failed to make significant market share.

[mystran]

Hmmh. Does "cable select" work based on the connectors on the cable, or signal quality?

Neither. "Cable select" requires a special kind of cable where one pin is not connected to the second connector, only to the first. Those special cables failed to make significant market share.

Ok, that's basicly what I had in mind for teh "based on the connectors". And if I am not seriously mistaken, almost every single IDE cable you see these days is cable-select compliant. I mean, I stopped caring about jumper settings some 5 years ago or so, and never had any trouble (and cable position identifies just fine).

Might it be that those just didn't catch on when they were first introduced, but since then no new non-compliant cables have really been manufactured so while the old non-compliant cables have slowly been replaced with new compliant cables, stuff has started working, without anybody really noticing?

This does happen with tech occasionally, I mean: something is first hyped, and fails to catch on, but is so ridiculously cheap to support that everybody starts supporting it anyway even if nobody really uses it, and at some point the support is universal, even if most people thought the whole technology had been abandoned years ago.

Or am I just incredibly lucky to find all my cables compliant?

[Solar]

And if I am not seriously mistaken, almost every single IDE cable you see these days is cable-select compliant.

You are mistaken, AFAIK. Virtually no 40-wire CS cables are around. The 80-wire type, however, is CS-compliant (because they burned it into the standard).

I mean, I stopped caring about jumper settings some 5 years ago or so, and never had any trouble (and cable position identifies just fine).

Some 5 years or so, you probably (smartly) started using 80-wire cabling.

Links I found on the matter:

http://www.pcguide.com/ref/hdd/if/ide/confCS-c.html
http://www.pcguide.com/ref/hdd/if/ide/c ... e80-c.html

[mystran]

You are mistaken, AFAIK. Virtually no 40-wire CS cables are around. The 80-wire type, however, is CS-compliant (because they burned it into the standard).

Ah, that explains it then. You won't plug hard-drives into 40-wire cables these days. =)

In fact, I think even my lonely CD-drive has a 80-wire...

[Candy]

Ah, that explains it then. You won't plug hard-drives into 40-wire cables these days. =)

In fact, I think even my lonely CD-drive has a 80-wire...

Nowadays, I only noticed that the 80-wire are less structural sane, as in, I've ripped one apart some time ago. Plus, I'm a student. So, I usually use a 40-wire cable . It doesn't really matter much still, the harddisks can't keep up anyway. Might matter if you have a bad setup in terms of master/slave, but I usually work those out nicely .

[mystran]

I'm a student too, and I've never bought a single IDE cable (40 or 80 pins) and IDE cables are definitely the LAST thing I have shortage for. For some reason, those just tend to appear out of nowhere, and fill every whole you can think of.

[distantvoices]

conjuring them outta thin air,are you? *rofl*

me uses 40 pin ide cables too for the 80 pin ones are still a wee bit expensive.

[Solar]

I found at least one 80-wire cable in every mainboard's box I purchased so far. (And in any systems that had more than one hard / optical drive each, I was using SCSI anyway.)

[distantvoices]

*chuckle* the grim mainboard reaper.

I've only bought new ones thrice till now. there were some ide cables. have to look which kind. due to affordability I ressort to ebay for goodies.

[Candy]

Due to cash reasons I rip apart old computers and reuse their cables. No surprise they have 40 wire cables .

More to the point, even the most modern harddisk can only start to push at the limit of 33MB/s and that in full-burst mode from its cache. Hence, for each and every type of normal usage (say, including some form of seeking) you might get up to 1-2% speedup with the new cables!. Now, I don't care about that much speedup for ?5-20.

Add to that that any IDE system will perform very poorly if you use both the slave and master connection, ending you up with my simple conclusion: make your system such that you will always transfer from one cable to the other and such. So:

My first cable holds my main drive + dvd player (never copying files locally when playing a dvd). Second holds my CD burner and my second harddisk (usually not copying from that hd to the cd burner since the other one is bigger and I do copy between hd's).


If you want performance, add a controller for two more cables and use that. It's not much more expensive but a lot quicker.