Does it make any difference if a 40 wire or 80 wire cable is used on the IDE channel where optical drives are connected? I just bought an OEM ND3500 that came without a cable. I will install it as master along with a Lite-On 48x CD /RW drive as slave on the same IDE channel. What are the benefits of 40 wire vs 80 wire cable in this example?

I don't think it makes a difference unless you have a 66 udma drive wich needs a 80 pin to go full speed.

(in reply to bradf)

Both are ok.

(in reply to S33K3R)

Anyone knows if the 80pins cable is grounded on the mainboard
side or on the drive side?
(I don't expect the 40 extra grounds to be grounded on both sides
as this would creates ground loops).

(in reply to S33K3R)

The connection is the same on both sides for both 40 or 80. The difference is the small cables for each, in one case are 40 while in other 80.

(in reply to mardigan)

Grounded on the motherboard side.

I'd only use 80-pin cables, even if I had UDMA33 drives.

Extra grounding only improves signaling. No harm comes out of using the 80-pin cables on motherboards that have the required UDMA100 (or later) connectors.

However, using 80-pin cables on motherboards that have non-UDMA100 connectors, is a bad idea. Without grounding, those extra conductors in the flat cable would act as antennaes.

(in reply to Iggy)

Drives and cable can be odd things

I find on my pc any pioneer with 80 or 40 pin cable will detect as DMA MW 2 unless its jumpered as slave with an other drive as master.

This has been the case with both my 107d and new A08XL, this seems to be something to do with windows xp and my intel chipset. I use stock xp EIDE drivers. I have only seen this odd problem with pioneer drives.

(in reply to Halcyon)

I have seen sometimes problem using 80pin cable, maybe with older devices, its not something like a rule, but in specific cases (combined with specific motherboards), using 40pin cable solves problems

(in reply to KenW)

quote:

ORIGINAL: Halcyon

Grounded on the motherboard side.
...
Extra grounding only improves signaling. No harm comes out of using the 80-pin cables on motherboards that have the required UDMA100 (or later) connectors.

However, using 80-pin cables on motherboards that have non-UDMA100 connectors, is a bad idea. Without grounding, those extra conductors in the flat cable would act as antennaes.

Well, well, well
The grounding is done inside the motherboard side connector of the flat cable, I guess?
So only the quality of the grounding/shielding of the motherboard PCB influence the
behavior of the cable, and the extra conductors in the flat cable won't act as antennaes
by being not grounded, but only by the PCB being badly designed...
Do you agree?

Another point:
On the 80-pins cable there is a pin dedicated to the recognition of the U-DMA66
property of the cable, <- I don't think this interfere with the shielding? ->

(in reply to Halcyon)

quote:

ORIGINAL: KenW

Drives and cable can be odd things

I find on my pc any pioneer with 80 or 40 pin cable will detect as DMA MW 2 unless its jumpered as slave with an other drive as master.

This has been the case with both my 107d and new A08XL, this seems to be something to do with windows xp and my intel chipset. I use stock xp EIDE drivers. I have only seen this odd problem with pioneer drives.

I would suggest upgrading the motherboard BIOS and/or replacing the cable with
another one of better quality (80-pins one if the motherboard is a recent one)
If swapping the PSU for a good quality (very low electrical noise) one solves the
problem, then that would be very informative!
Hope this give you some help!

(in reply to KenW)

A few drives are beginning to go to UDMA 4/ATA-66 (Liteon 1633S, not sure if it's the original or just some rebrands), and maybe others - some DVD-ROM and combo drives use UDMA 3/ATA-44.

I now have two 80 wire cables, and run all drives in CS mode (so I can pull out an old drive, and just set the new drive to CS - also graet if i have to adjust which drives share with what).


There ARE some problematic combinations, but older drives should be able to work with 80 wire cables - as already mentioned, it's a bad idea to use 80 wire cables with motherboards or controllers that don't support at least ATA/66

(in reply to mardigan)

Normaly when a drive cames with a 40 pin cable this is what it needs. If it comes with an 80 then 80 is what you need, as in the case of BenQ DW800.

(in reply to Matthew)

mardigan,

I was being too terse and let myself be misunderstood.

Yes, the 80-pin cable is only grounded on the motherboard side.

However, with older motherboards (ATA, UDMA33 controllers) there is not necessarily grounding for the extra 40 conductors in the 80-pin connector. In such a case, the ungrounded extra 40-conductros could act as antennas, which would be bad for signaling.

The standard from 40-conductor to 80-conductor cable changed at UDMA66 introduction.

Of course, with a motherboard that has a proper UDMA66/UDMA100/UDMA133 connectors, there should not be these problems. Or, the problem is only down to the motherboard PCB implementation as you state.

Emperor,

thanks for the addition! I haven't had any problems with 80-pin cables with older drives (as long as the motherboard is new), but it's good to know that too.

Basically I use just flat, teflon constructed 80-pin cables from Granite Digital. They have worked the best for me, even on chipsets that can be quirky on longer cable lengths (like nForce2/nf3).

I haven't had problem with them even on older UDMA33 devices that ship with 40-conductor cables.

regards,
halcyon

(in reply to Iggy)

Yes i had face some problems with specific motherboard chipsets (ATI) and specific drives, 80pin cable didn't worked very well..

(in reply to Halcyon)

OK, thanks for the clarification.
I thought that the 40 ground wires were connected to the standard
ground pins inside the connector.
This seems to be true for some connector's manufacturers:
http://www.circuitassembly.com/EngineeringDrawings/610191k.pdf
hence the importance of a good quality cable (with good connectors)
Thanks again

(in reply to Halcyon)

As I see it, the extra 40 wires cannot possibly be grounded at the motherboard. Although there are 80 wires, there are still only 40 pins. To connect the extra 40 wires to ground at the motherboard would require an extra 40 pins for the extra 40 wires. As we don't have an extra 40 pins to connect to, the only possible way the extra 40 wires can be grounded is in the connectors on the ribbon cable.

(in reply to mardigan)