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View Full Version : does HDD cable length matter???



chadc281
09-10-2002, 07:09 AM
I read an old article just a second ago describing what udma mode 2 is and how it works. It said that in order to get the capable speed you need to have a cable that is 18" or shorter. Now obviously this is an old article but i've never heard this before. My cables are 24", would i recieve faster HDD speeds with a shorter cable?

Thanks!

FLaCo
09-10-2002, 08:11 AM
I have been told from a few here to keep it under 18" if possible. After that data transfer rates may suffer a bit.

bigjackusa
09-10-2002, 09:16 AM
It's more a rule of thumb I think. It doesn't make data transfer faster with a shorter cable, but the 18" recomendation is to insure that there is no data corruption or loss. The longer the cable, the greater potential for damaged data streams. It has been my experience that these types of limitations are rather conservative figures. (I use some 24" ide cables too. I have used longer scsi cables than recommended without problems as well.) I would think that they probably look at, say a thousand computers and try 18" cables. They find no problems. They try 24" cables and 3 have problems. Since these recommended specs are looked to even by organizations with mission-critcal info, they suggest an 18" limit.

Wiggo
09-10-2002, 11:16 AM
Yes 18" ones are fine but I've had to replace quite a few 24" ones though due to bad signal degeneration. :smokin:
<center>:cheers:</center>

Gilad
09-27-2002, 07:19 PM
Usually at home you will not have any problems, but when writing the specs they had in mind production plants that may have quite a bit of EMI (Electro Magnetic Interference).

sKuLLsHoT
10-01-2002, 11:40 AM
it can be slower, maybe not noticable all the time, but it is, this is something to do with the way data is sent along the ide interface, apparantly a data signal is bounced back down the ide cable to let things know when its safe to send more data, and when the cables longer, it can cause the equivalent of a network broadcast storm...although on amuch tinier short-lived version..

{PoSeIdOnAs}
10-09-2002, 06:47 AM
and if you use the rounded cables that are twisted and shielded with aluminum or copper , the extra length I bet causes fewer problems than the 80's type ribbon cable....also assuming you get the cable from some respectable company (all cables are *not* the same with the rounded ones).

Mine is from Vantec and it is "silver" (clear basically) with aluminum mesh covering the cable in between the heads with the wires twisted to reduce cross-talk between them. I have this connecting both my burner and CDROM drive since last november and so far not a single problem ever encountered...and everything is flying just like it did with the ribbon cable.

If you use non-twisted cables it causes cross-talk and drives will "fall off" the My Computer window !!! Meaning they disappear because interference is causing some rather strange anomalies :laugh: And the sheilding protects the cables from any outside interference as well.

Seagate cables are real good as well. But now that I found out I can actually, and i hope without slowdown, put my single HD on one of the RAID channels with the ZIP on the other RAID channel, and then have my burner on IDE channel 1 with the CDROM on IDE channel 2, I'll be getting yellow ones for the RAID channel and another clear one for one of the regular IDE channels.....


but yeah smaller cable lenght *always* improves data reception no matter how good the cable it, in the real world, has its own wire resistance and this always decreases data integrity as it travels along. It may seem negligeable but something is bound to happen one day:cantfocus