talking about cables

[Guest]

hmm, that reminds me ....
I have a 100 ATA Ibm drive with 7200 rpm.
My computer is a AMD 750 processor. About the motherboard,..
It seems that I've lost the manual, but it can go with the pc133 sdram, so I assume that it's ATA 66 at most ...
I did a benchmark on the computer's hard drive, and the result was that it can only go to 5500Kb/s. That drove me mad ... (because I saw a bench result on an ATA 66 with 5400 RPM running twice as fast as my hard drive)
Then I went balistic looking for options, like Prob it was because I ran the dma5 when my computer can only support dma4? I slowed down the hard drive internally and it didn't worked.
Finally, I unplugged the zip drive that is connected to the drive (same slot), and it went up to 8000 Kb /sec.
Could it be because I use the wrong cable?
(When I bought one, the staff there explains that there is only one IDE cable, but then again, I read someone's post in here and it makes that staff looks like an idiot!)
Can somebody explain this to me and confirm whether that guys is an idiot or not?
thx

 

[Guest]

Basically two type of cables

1. 40 conductor ATA33

2. 80 conductor for ATA66 & ATA100
the extra 40 conductors are really 'grounding wires' to reduce errors.

Cheers.
hell out

 

[Guest]

do you think that having the wrong cable can cut the speed by that much?

 

[Guest]

Yes it can, however this may not be a problem. Having the zip drive in the same cable as your drive may be.
Try relocating your zip drive to another controller port ( probably the same one as your CD ROM ).
Now this may or may not help, and may introduce other problems.
So, its only offered as a suggestion.
Do some more checking, to see if this may improve the situation.
And remember, any changes you do at your own risk .

Cheers

hell out

 

[Guest]

hmm, come to think of it, the ata33 cable won't fit to the ata66
prob my problem is not that, but something else ...
Now, the max speed that I can have is 7500 Kb/sec
on DMA 4, is that normal?

 

[blah]

It is not the cable you are having problem with, it is a Zip you have with the hard drive on the same cable. Usually drive will work up to speed with the slowest link on the IDE port. Port does not allow different speeds, it is like a RAID, you can have space only up to the smallest drive on the chain. So if nothing is on the way, hard drive will go as much as controller will allow, otherwise controller will "adjust" everything to the slowest. Hope that helps.

Post, we'll do the "search"...

 

[dmcmahon]

Can you clarify what you mean by "runs at the speed of the slowest device"? Surely since PIO or DMA is selectable by device even on the same chain, you're not stuck running PIO mode just because one device needs it? Also, surely you're not stuck by the actual media transfer rate (e.g. Zip drive and HDD on the same IDE does not mean the HDD runs at the transfer rate of the Zip disk)? Do you mean DMA mode, like if you put an ATA33 and ATA100 disk on the same ATA100-capable cable, you will still be stuck with ATA33 for the DMA mode? Ditto combinations involving ATA66? Thanks.

 

[dmcmahon]

Both cables fit any IDE drive, they both have 40-bin female connectors. The difference is the ATA66/100 cable has 80 conductors (40 extra grounds). I believe the software can sense this and requires the 80-conductor cable to enable ATA66 or ATA100, otherwise withe the 40-conductor standard cable you go at ATA33. Few users would notice much difference; even with the largest consumer drives spinning at 7200rpm, the transfer rates on the outer tracks peak out around 40 Mbytes/sec give or take; I know of no consumer IDE drive that can sustain even 66 Mbytes/sec (you might be able to fake it with RAID, though).