Special IDE cable requirements.

[aaron]

The distance between the master and slave connectors on the IDE cables that I have (or have ever seen) is only about 4" (or so)... I need a master-slave span of about 8" in order to connect a secondary master HDD and a slave DVD-RW in my comp's case. :roll:

Can you guys please suggest some outfits where I can get an IDE cable that will do the job?

Thanks!

 

[i]

I know this may seem a little like a tangent (and I guess it is), but do you have any unused PCI slots left?

 

[aaron]

Yeah, I thought about adding an ATA100 card as a last resort. Since I don't really need additional IDE channels, I'd much prefer getting the right cable (less cost). :wink:

 

[Mercutio]

Try callcct.com.

 

[i]

To even have a chance at decent performance you only want one device per IDE channel anyway (and forgive me if that's old news to you but I haven't seen you here before ... hi, by the way).

I think Promise is the oft-recommended basic option for ATA controller cards (someone? anyone?) these days. ZipZoomFly has a U100 card for $30.00 with free shipping, and NewEgg has a U133 card on sale until tomorrow for $37.00, shipped.

Or yeah, you could try callcct.com

 

[aaron]

Yup, I'm new here (thanks for the welcome mat)... Ya know, I've heard that before - i.e., sharing the IDE cable between a hard drive and an optical device will slow access to the hard drive. However, I don't see why that should be (especially with late model devices). :?:

Besides which, the hard drive that's being shared with the DVD-RW will only be used for backup, so even if the above is true, I don't think it matters in my case!

 

[i]

You've heard it before because it's true.

And yes, I'm sure your hard disk drive and DVD-RW drive are very capable, late-model devices. But your IDE controller is what most all of us have for an IDE controller ... a rehash of a very old device. How long has the plain IDE interface in one format or another been around for now? 15 years?

Storage Review has an excellent reference section that covers a bazillion points, including the issue of multiple ATA devices on a single channel:

Master/Slave Channel Sharing: By its very nature, each IDE/ATA channel can only deal with one request, to one device, at a time. You cannot even begin a second request, even to a different drive, until the first request is completed. This means that if you put two devices on the same channel, they must share it. In practical terms, this means that any time one device is in use, the other must remain silent. In contrast, two disks on two different IDE/ATA channels can process requests simultaneously on most motherboards. The bottom line is that the best way to configure multiple devices is to make each of them a single drive on its own channel, if this is possible. (This restriction is one major disadvantage of IDE compared to SCSI). An add-in controller like the Promise "Ultra" series is a cheap way of adding extra IDE/ATA channels to a modern PC.

So, you've got a hard disk and DVD-RW drive on the same channel. That should be ok so long as you won't ever need to use those 2 devices at the same time.

But the safer, more professional route would be to install another controller as an add-on PCI card. Either that or move up to Serial ATA (SATA). By design, you can only attach one device to each channel in a SATA setup.

 

[i]

Oh hey, I completely missed this quote:

Hard Disk and ATAPI Device Channel Sharing: There are several reasons why optical drives (or other ATAPI devices) should not be shared on the same channel as a fast hard disk. ATAPI allows the use of the same physical channels as IDE/ATA, but it is not the same protocol; ATAPI uses a much more complicated command structure. Opticals are also generally much slower devices than hard disks, so they can slow a hard disk down when sharing a channel. Finally, some ATAPI devices cannot deal with DMA bus mastering drivers, and will cause a problem if you try to enable bus mastering for a hard disk on a channel they are using.

 

[time]

In theory, you should be able to remove the second connector and reposition it elsewhere on the cable. Look for some sort of latch at each end of the connector; it will probably involve inserting a very small screwdriver to release it.

The connectors are really only designed for single use, but I seem to recall doing this in years gone by.

 

[Mercutio]

One more note if you're considering a longer cable: If one of the two devices you're proposing is Ultra/66 or better, don't buy a cable longer than 24". I assure you that anything longer won't work.

 

[aaron]

Master/Slave Channel Sharing: By its very nature, each IDE/ATA channel can only deal with one request, to one device, at a time. You cannot even begin a second request, even to a different drive, until the first request is completed. This means that if you put two devices on the same channel, they must share it. In practical terms, this means that any time one device is in use, the other must remain silent. In contrast, two disks on two different IDE/ATA channels can process requests simultaneously on most motherboards. The bottom line is that the best way to configure multiple devices is to make each of them a single drive on its own channel, if this is possible. (This restriction is one major disadvantage of IDE compared to SCSI). An add-in controller like the Promise "Ultra" series is a cheap way of adding extra IDE/ATA channels to a modern PC.

No arguing about that...

Hard Disk and ATAPI Device Channel Sharing: There are several reasons whtical drives (or other ATAPI devices) should not be shared on the same channel as a fast hard disk. ATAPI allows the use of the same physical channels as IDE/ATA, but it is not the same protocol; ATAPI uses a much more complicated command structure. Opticals are also generally much slower devices than hard disks, so they can slow a hard disk down when sharing a channel. Finally, some ATAPI devices cannot deal with DMA bus mastering drivers, and will cause a problem if you try to enable bus mastering for a hard disk on a channel they are using.

No disrespect intended, but I just can't buy this (yet)![/quote]

But as I indicated, on the cable in question in my case, the use of only one device will be requested at any given time![/quote]

 

[aaron]

In theory, you should be able to remove the second connector and reposition it elsewhere on the cable. Look for some sort of latch at each end of the connector; it will probably involve inserting a very small screwdriver to release it.

The connectors are really only designed for single use, but I seem to recall doing this in years gone by.

Now that's very interesting. I never thought of doing that. :idea:

 

[aaron]

One more note if you're considering a longer cable: If one of the two devices you're proposing is Ultra/66 or better, don't buy a cable longer than 24". I assure you that anything longer won't work.

No problemo... while I need an 8" span beween device connectors, I do not need that long a cable!

 

[Handruin]

Another suggestion...if your motherboard has SATA built in, you could buy a SATA to PATA converter and avoid the irregular PATA cable length.

 

[Bozo]

Antec makes cables with somewhat wider spacing. I got mine at www.newegg.com.

Bozo :mrgrn: