Will these 4 ATAPI (IDE) devices coexist?

I have a 200mHz Pentium MMX (on an Intel THX430HX board, circa 1996)

I've recently successfully installed 3 devices on the IDE ports. The HDD sits alone on the primary port. The secondary port has a CD-ROM at the end of the cable as master, and a Seagate Travan Backup Tape drive (per Seagate recommendations: avoid having tape drive on same port as hard drive, and mount it in the middle as slave).

Is there any reason that I might expect any problems putting a second CD device (CD-RW) on the primary cable with the hard drive? If so, which is best, as master or slave, and where on the cable is best?

Thanks in advance for advice. If this should work, I need to buy the cable to try it.

Terry Quinn

 

I see no reason why it shouldn't work...

However it's said that the slowest device on the chain (in this case the CD-RW) will dictate the speed of the datastream going through the bus. Which means you may lose some performance from the HDD, but if the HDD is as old as the rest of the machine it is probably an ATA-33 unit and would therefore not suffer to the extent that a more modern ATA-66/100/133 unit would.

 

It sounds like I should do a little HDD benchmark before and after the installation of the additional device to check on performance.


Any thoughts on location on the cable or which device should be master (HDD?)

 

I don't believe that the location on the cable really matters on ATA-33. However, some of the newer IDE cables have master and slave printed on them, and the master is the connector at the end of the cable and the slave is the middle connector. So that's the configuration I would use as well. It's also easier to see at a glance which is which without having to look at the jumpers.

Regarding which to set as master and which as slave... I can't say that it would make a difference, but my instinctive reaction would be to put the fastest unit (the HDD) as the master and the CD-RW as slave.

Another option you have, if you have any free PCI slots, is to buy an ATA-100 controller and put your HDD on that and keep the CD-RW on the built-in controller. That would prevent a possible slowdown from having a slower unit on the same channel as the HDD - besides if the HDD is an ATA-66 or faster you should notice a performance increase just from having the controller, and the correct 80 wire cable - and they are not all that expensive if you don't need the RAID functionality.... it will also allow you to add another HDD at a later time if you so wish.

 

Thanks for the suggestion about the extra card, and the other information. That will give me an option if I do have a problem with the speed.

Terry

 

Just to wrap this up:

I've completed the installation of the four devices and everything is working fine. I have the tape drive and a CD-RW installed on the secondary IDE port with the tape drive as slave.

On the primary, I have my HDD as master, and a CD-Rom as slave.

I tested the performance of the HDD before and after installing the CD-ROM to see if it would degrade the HDD's performance. It did not.

The test was comprised of copying 5 very large files (29 meg to 72 meg in size) from the C: partition to the D: partition of the HDD. I made sure that this was repeated enough times so that if there was benefit of buffers, that benefit would stabilize, however that did not matter.

This copy operation took a little less than 2 1/2 minutes with my hardware. The time did not increase at all after I installed the CD-ROM on the same interface as the HDD. So with the hardware that I have, the placing of the slower device (CD-ROM) with the HDD did not cause a slowdown of the HDD.

Thanks for the help.

Terry