if a hard drive is ata66 or 100 (master) and a cd-rom, zip or ata33 device is connected as slave, will the HDD only transfer as fast as the slowest device? http://www.PCGuide.com/ubb/confused.gif

My understanding of issue is that if two devices of differing speeds are hooked to the same IDE channel then the transfer rate will be that of the lowest speed device on that channel.

------------------
mjc
To ME or NOT to ME....

Actually, with the ATA-66 & 100 its the device itself and the cable from that device to the mobo and the motherboard support that determine the speed of transfers.......so it wouldn't matter what else was on the cable with the faster drive (device). I think it will work fine! You can benchmark it against other similar drives to see if it is doing what it's supposed to.

------------------
When all else fails...I'm a heck of a parts swapper!

The controller will only "talk" as fast as the slowiest device on it's channel. The standard recommendation is to only pair up hard drives on the same channel. When you enable one device as a slave you have turn off it's onboard controller and the controller of the master device is now "controlling" both the master and the slave IDE devices. This controller will only transfer information at the rate that both devices can understand.


Hope this helps http://www.PCGuide.com/ubb/smile.gif

------------------
"It's just a whisper in my Ghost"

ok. let me see if i got this straight. if an ata100 hdd is primary master and a zip is primary slave, i'll only be able to transfer between the two at the speed of the zip drive? (the zip should not affect transfers between hdd partitions, right?) on the other hand, if there is only an ata100 hdd on the primary and an ata33 hdd on the secondary, then the transfer rate is the that of the ata33? thanks for helping me clear this up.

Yes, On a IDE channel only one device can be active at a time.(SCSI on the other hand does not have this limitation.) So if your transfering files from the hard drive to the zip. The files will be transfered at a rate that the zip drive can understand. This "rate" will be slower than ATA100.(this would not affect transfers between partitions on the same drive)

This is also true if your moving files from any (outside) location to the hard drive. The controller will "talk" only at a rate that both devices on it's channel can understand. This is why the standard recommendation is to not place a CD-rom,zipdrive,..etc,etc on the same channel as a hard drive.


Please note that if your hard drive is a primary master and your zip is a secondary master. Than they are on different channels and the speed of one won't affect the speed of the other.( unless of course your transfering files to/from the zip.)


Now as to if you'll notice the speed difference that's another matter. Because most hard drives do not max out the ata33/66/100 channel that their setting on.

Hope this helps http://www.PCGuide.com/ubb/smile.gif

------------------
"It's just a whisper in my Ghost"



[This message has been edited by Ghost_Hacker (edited 02-14-2001).]

Here is an interesting quote from the good folks at Storage Review.com regarding this matter:"The main problem when it comes to looking at interface performance is that on modern systems, the speed of the interface is not the limiting factor to overall hard disk performance. If a given hard disk can't read data from its platters fast enough to saturate an interface of a given speed, going to a faster interface yields improvement only on reads of data already in the drive's internal buffer--which makes virtually no difference in overall, real-world performance. Despite this, companies try to claim that (for example) drives using Ultra DMA/100 are "50% faster" than those using Ultra DMA/66. In fact, at the time of this writing (late 2000) no IDE/ATA drive can saturate even a 66 MB/s interface, so going to 100 MB/s is essentially pointless. "

------------------
When all else fails...I'm a heck of a parts swapper!

Ghost_Hacker: thanks for the help. so you'll transfer at the rate of the slowest device you're transfering between (whether or not it's on the same channel). the only difference is that it may be faster to transfer between two devices on two seperate channels because they can "talk" at the same time.

Yep...you got it.

------------------
"It's just a whisper in my Ghost"