UDMA100

[Jumby]

When I rebuilt my system a while ago and put in a UDMA100 7200rpm WD hard drive and turned on machine nothing came on the monitor (this has been a while so I'm trying to remember it all). I changed the cable to a regular 40 wire and it worked fine. I tried the 80 wire again, still nothing. So I put the 40 wire back on and just went with it. But, I'd like to get the full impact of the hard drive. I also have a Zip 100 on same cable (could this be the problem?). I have a CDRW too and TDK says it has to be on separate cable. Any suggestions?

[Rick]

I can say for sure that the Zip drive is the cause but I’d be willing to bet a small amount on it.


Put the Hard drive on the master / primary channel using the 80 wire cable.
Set the Hard drive as Master and IF it has a Jumper for single drive use it as well.

Then Using the standard 40 wire cable
You should be able to Place the CD-RW and the Zip on the same cable.
CD-RW as master and the Zip as Slave on the secondary channel

[saphalline]

Rick is most definitely correct. Unless you're running some fancy SCSI and/or RAID set up, your primary hard drive should be all by itself on its own IDE channel.

Once you add another drive (even another ATA/100 hard drive) you slow down that chain because of course IDE isn't meant to access multiple drives at once. So two hard drives actually gives you less than half peak performance (inefficiencies cut it below half) whenever both drives need to be accessed at once.

Also I think 80-pin cables are rated a minimum of ATA/66 and most other drives are only ATA/33, so your hard drive AND your other drive got confused with the bus traffic probably.

[iisbob]

ATA ( or UDMA as is commonly seen nowadays ) 80 wire cables work ok with older 33MB's persec drives-the extra 40 wires ( not pins, they still use the same 40 pin structure as the older 40 wire cables ) are for more grounding, they help prevent what's known as " crosstalk " { similar concept in twisted pair ethernet cabling } so they cut down on the signal inteference from the other eletrical devices in you system.

On the whole, you'll generally see about a 10-20% increase in performance by using the new 80 wire cables on older drives. Most all new drives require them, and tho they will boot with 40 wire, you'll usually see an error upon startup about it.

...because of course IDE isn't meant to access multiple drives at once

I believe what you actually meant to say was that ide can't access multiple channels at the same time-ie, you can't have data moving from primary master & secondary slave drives at the same time, however you can have the cdrom on secondary master and the hd on primary master exchanging data at the same time. Of course this isn't true for SCSI or the new serialATA intrerface, they will/do support multiple channel access at the the same time.

The reason an UDMA100 rated drive slows down if on the same channel as a UDMA66 drive is because the ATA standard only allows for the data transfer rate of the fastest capability of the slowest peripheral { drive }, which in this case would be the UDMA66 drive. In truth you would not see any performance decrease by using this combo becasue the average sustained data transfer rate of 66/100 drives is only around 40-50 MB's persec. You would notice a difference if this was a combo of 33/100 tho. That is why you shouldn't put ATAPI peripheral's like CD/CDRW/DVD on the same channel as your hard drive; they can only transfer data in 33 MB's persec burst rates, and have a sustained data transfer rate of about 20-25 MB's persec rate. DVD drives transfer at a greater rate of course than CD/CDRW drives.

Zip drives have always been notoriously troublesome-seemed like a great idea at the time they were introduced, but thank GOD the CD standard evolved to replace it with a larger stoage capacity and ease of use.

i suggest getting rid of the Zip drive. http://www.PCGuide.com/ubb/smile.gif



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iisbob

Computer-Show me the Enterprise; no bloody A, no bloody B, and no bloody C-just the original...Mr Scott { from a STNG episode }

[mjc]

I'm with iisbob 100% on this one... http://www.PCGuide.com/ubb/tongue.gif



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mjc
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