G
GTS
Hi I thought the max you could use on ATA133 was 18", but have seen several
24" ones around - are these OK to use?
TIA
24" ones around - are these OK to use?
TIA
W
Will Dormann
GTS said:
Avoid cables beyond 18" if at all possible.
Since they're beyond spec. you may experience decreased performance or
other troubles.
-WD
G
GTS
OK thanks!
Will Dormann said:
E
Eric Gisin
They are fine for one ATA100 device.
T
Timothy Daniels
Will Dormann said:
Yes, they *are* contrary to ATA specifications, but lots of people use
'em without problems - including me, and that is with ATA/133 hard drives.
They're frequently found in the "round cable" form and used by guys who
have lots of HDs in a large tower case and/or who want to avoid restriction
of the air flow - which can happen with flat cables. I prefer the type with an
aluminum braid around them on the theory that the aluminum braid acts to help
shield the data wires. If they introduce bit errors, I haven't noticed any.
YMMV.
*TimDaniels*
G
Guest
GTS said:
In practice it almost always works, but I'd rather have a cable that
long to be made up of twisted pairs similar to those found in LAN and
SCSI cables. Twisted-pair cable easily supports 36" ATA100 (I didn't
have an ATA133 controller or drive) and seemed to work fine even over
60".
I don't know of any reason why an IDE cable over 18" would be needed
for a 3.5" HD, and if I had to use drives in 5.25" bays I'd rather get
a deeper case that allows them to sit in front of the motherboard
rather than above it.
G
Guest
Timothy Daniels said:
I don't because in many of those cables the braid isn't grounded, as
it should be, so it can act as an antenna (receiver and transmitter)
rather than a shield. Twisted-pair wires are much better, and many
round cables are made with them. One maker of round cables even
admitted that its products were merely for decorative purposes.
How have you tested? Windows will slow down or turn off DMA if it
encounters HD errors, and throughput isn't a good measure because
drives can't sustain transfers much faster than 50 MB/s.
G
GTS
Well I have a pretty bog standard ATX case but I find the standard length
too short if I want to have a HDD as master and an optical as slave on one
channel - the 3.5" bays are always at the bottom and the 5.25 at the top.
Yes I could use a 5.25-3.5" caddy but if a longer cable works why bother?
too short if I want to have a HDD as master and an optical as slave on one
channel - the 3.5" bays are always at the bottom and the 5.25 at the top.
Yes I could use a 5.25-3.5" caddy but if a longer cable works why bother?
T
Timothy Daniels
do_not_spam_me said:
In *none* of the "round" cables is the braid grounded.
But the braid still acts as a shield at high radio frequencies.
Even with shielded twisted-pair LAN cable, there is debate
on whether to ground just one or both ends of the shielding.
With high frequencies, where the wavelength is comparable
or shorter than the length of the cable, shielding can be
effective without being grounded. Just the mechanism of
reflection can be beneficial. In the case of "round" cables,
ground "shielding" is provided by the ground wire which is
twisted together with each data wire.
All the ATA/100 or /133 "round" cables which I've seen
or heard about have a ground wire twisted together with
each of the 40 data wires. This is not "twisted pair"
in the sense of balanced differential signals, but the
close proximity of the ground wire provides a degree of
protection from crosstalk, just as it does with flat cable.
My only test has been large file transfers between
hard drives - which occur at about 98MB/s.
*TimDaniels*
T
Timothy Daniels
do_not_spam_me said:
Which "pairs" of wires would you twist together?
How do you attach each of the 80 wires to the
ATA 40-pin connector?
How do you ground each of the 40 ground wires?
How did you test for "seemed to work fine"?
Some people are stuck with what they already have in
the way of case and motherboard.
Some people use a PCI ATA controller card that places
the controller connectors farther away from the drives
than the motherboard's connectors.
*TimDaniels*
G
Guest
Timothy Daniels said:
You make good points, and for those situations I've mounted hard
drives vertically on the floor of the case, after drilling holes in
it. This can also benefit cooling since it puts the drives right in
the path of the case fan.
A
Andy Lee
Not true I have a round cable at home with a ground wire from the
braid which attaches to the MB mounting screw near the ATA sockets
I cant remember the make off the top of my head but it is black and
very well made with a foil cover over the ends of the wire where they
transition from the round section to the actual connectors.
T
Timothy Daniels
Andy Lee said:
How many wires are there which enter the connector?
That ground wire connected to a mounting screw sounds
inconvenient. I wonder why the manufacturer didn't use
the ground in the connector itself - the one that grounds
the 40 ground wires. There *are* 40 white ground wires,
right? Who sold it to you?
*TimDaniels*
A
Andy Lee
There are 40 ground wires. It is recognised by the system as a 80 wire
cable at least it lets UDMA 5 devices run as such. The ground wire is
inconvienient only if you connect/disconnect cables on a regular
basis, something I'm not inclined to do. If I change a drive I usually
leave the MB connector attached and only disconnect the drive end.
I brought the cable from a local supplier, when I get home at the end
of the week I will take looksee and let you know who made it. I was
attracted to the cable because it is so much better made than a lot of
the round cables I have seen/brought in the past.
Having said that I have only had problems with one of these which was
very picky about how it was routed with out causing drive connection
issues.
All my HD's are now serial ATA and the connectors/cables for that are
so much easier to manage and my only real want from them now is the
provision of a shorter cable as the SATA ports on my MB are very close
to the back end of the DRives and the standard cables are probably
twice as long as they need to be.
T
Timothy Daniels
Andy Lee said:
It will be interesting to see the brand name. From my
personal observation from looking at web photos, from
seeing them in the stores, and from actually calling some
of the distributors, it seems that there are only about
three manufacturers - all of them in Asia - despite there
being many brand names. But... I imagine that there is
also a cottage industry since they're low tech and labor-
intensive to make.
When I finally got my hands on a physical SATA cable,
I was surprised by how rigid it was in side-to-side bending
(as opposed to forward-and-back). Does that feature
give you any routing problems? Maybe the cables are
long to accomodate that stiffness.
*TimDaniels*
A
Andy Lee
Right I've had a look and they are made by Antech. Presumably the same
Antech who make cases. They have black moulded rubber boots at each
transition to plug from cable with as I said a foil sheathing over the
wires. The main cable has a woven nylon sheathing not like most of the
cables which use a rubber tube. This woven stuff is the same as
Enermax use on their power supply low voltage cables
That sounds highly likely I just put a loose loop in the cables to
reduce the length.
Regards
Andy Lee
T
Timothy Daniels
Andy Lee said:
I've seen those cables. They might be made here as one of
the places said, when I called them, that they could make
them to any length that I want. I passed on it since I didn't
know they had foil shielding and they were... uh... ugleeee.
*TimDaniels*
A
Andy Lee
I've seen those cables. They might be made here as one of
the places said, when I called them, that they could make
them to any length that I want. I passed on it since I didn't
know they had foil shielding and they were... uh... ugleeee.
Ugly don't bother me, function does! I don't see the inside of my PC
all that often and it's not something I have any need to show off to
anybody else....
Regards
Andy Lee