D
DJW
Can I put a hard drive on a secondary IDE ATA bus? Is an old ata hed disk and am I right that it will be slowed down a bit in read write speeds. I want to put it in as a slave and the master on that second bus is a CD-RW drive.
L
Loren Pechtel
It should work, albeit slowed to the capability of that controller.
You'll have to set the jumpers--anything reasonably modern will have
directions on the drive for how the jumpers should be configured.
F
Flasherly
The end connector of the cable is master if both optic and HD are pin-
jumped for CS. Go to the master/slave pins only after that fails. A
better BIOS will also allow you to select which one to boot, past how
old, what brands like other brands, without further compatibility
issues. Best just to try the combinations and see what happens. Also
look at your HD speeds with and without the optical drive connected.
Most MBs only have one PATA port, and, ideally, each can't have its
own dedicated ribbon. Even if all works, you'll still have to be
careful about what you're doing, as there may be complications, time-
outs involved due data interruption if both drives are active. Some
programs or the OS don't recover well when thrown a curve ball.
P
Paul
DJW said:
If you have any pet theories, you can put them to the test
with an HDTune read benchmark.
Run your hard drive on your "best" bus first, to establish
a baseline graph. You should get a smooth, declining curve.
If the curve has significant flat areas, that can
represent a "bus bottleneck", possibly a cabling or
interface speed issue.
You can see in my comparison here, of SATA running at
SATA I or SATA II, what "clipping" of the curve looks
like when the bus is too slow (upper graphs). At the
very beginning of the graph, the cable rate is limiting
sustained transfers.
http://img829.imageshack.us/img829/842/500gb3500418ascomposite.gif
Then use your suspicious "secondary" IDE, connect one or
two devices to the cable, and repeat the HDTune test. What
did you see ?
I'm willing to bet, no difference. The two devices are
supposed to be independent on the cable.
(If one of these links doesn't render right, try the other.
Page uses old style frames.)
http://www.pcguide.com/ref/hdd/if/ide/conf_Performance.htm
http://www.pcguide.com/ref/hdd/if/ide/confPerformance-c.html
"Independent Master/Slave Device Timing:
Hard disk controllers on modern systems support running
the master and slave device at different speeds, if one
supports faster transfer modes than the other. Some systems,
however, especially older ones, do not. If you are using
two devices with radically different maximum transfer rates,
and the chipset doesn't support independent timing, you will
slow down the faster device to the speed of the slower one."
Now, the paragraph next to that, is a bit disturbing.
"Hard Disk and ATAPI Device Channel Sharing: There are
several reasons why optical drives (or other ATAPI devices)
should not be shared on the same channel as a fast hard disk.
ATAPI allows the use of the same physical channels as IDE/ATA,
but it is not the same protocol; ATAPI uses a much more
complicated command structure. Opticals are also generally
much slower devices than hard disks, so they can slow a hard
disk down when sharing a channel. Finally, some ATAPI devices
cannot deal with DMA bus mastering drivers, and will cause a
problem if you try to enable bus mastering for a hard disk on
a channel they are using."
I can understand a comment about performance, in terms
of the slow optical device occupying the bus for relatively
long periods of time, if both the optical and hard drive
are accessed at the same time. But in my experience, with
modern gear (where the optical and the hard drive, are
both using DMA modes), I feel the first paragraph applies.
As far as I know, a modern optical and modern hard drive,
support independent timings.
And you can prove this for yourself, and for the world,
with some HDTune benchmarks. Don't take my word for it.
The free version of this, is good enough for cable
rate testing, with optical installed or not installed,
with optical as master or as slave (the other device
being jumpered for the opposite of the optical).
http://www.hdtune.com/files/hdtune_255.exe
Paul
M
Mike Tomlinson
F
Flasherly
May as well. Can't really put money on your mouth.
D
DJW
What is the difference between an 80 and 40 ribbom cable?
F
Flasherly
Ghosts effects were being introduced into the machines due to the
killing off of older IDE standards, whose former pathways, on 40
ribbons, permitted spurious and erratic behavior that wasn't there
before.
P
Paul
DJW said:
On the 80 wire cable, every second conductor is a ground.
The effect of that, is to better define the characteristic
impedance and cut down on crosstalk. The same number
of "functional" signals (40) continues to exist. The end
result is, it is possible to support higher transfer
rates.
And I actually wrote my answer, before finding this one
Honest http://www.answerbag.com/q_view/891179
I was using the search engine, to try and find some pictures
of the signals on the IDE cable, but no luck. I can promise
you, the signals are ugly looking.
Paul
L
Loren Pechtel
They look almost the same. The faster PATA interfaces require the 80
wire cable. Note that both versions still have only 40 pins on the
connector, the extra wires are shields to decrease coupling, they do
not carry signals.
G
GMAN
Has NOTHING to do with what he asked
C
Chris S.
40 ground wires...
F
Flasherly
Crosstalk is ghosting.
Y
Yousuf Khan
Very little, except that the additional 40 pins were all used for
grounding. The 40-pin and the 80-pin cables were otherwise downwardly
and upwardly compatible with each other, with performance differences of
course.
Yousuf Khan
G
GMAN
Then why didnt you say crosstalk? Google translator sure is a bitch!
F
Flasherly
I prefer entropy...
(Communication theory) a numerical measure of the uncertainty of an
outcome.
It's almost spiritual, so soothing to not know within some probability
what perhaps we never will.*
*(In Greek mythology there's a state of man graced, when men are
depicted facing backwards with their torsos reversed, in contrast to a
more familiar state of biblical grace of naivety prior to succumbing
to temptations posed at the Garden of Eden. Man as self-sufficient in
both instances, as well whose composure the fates reserved as one
fallen from that such a noble state. The Greeks, however, later
diverged to manifest elevated gods to a state of revered immortality
[man knew, then, he lacked presumably withal in endless time to know
all]. One such particular god, Eros, perhaps was so created by the
gods, themselves, as a compensatory measure to a mortal mankind --
lacking a former grace for walking forward whilst facing backwards --
that he might take take what consolation sharing love proffers, amid a
like kind of beings, none of whom, may claim perfection. As both to
Greeks, and a modern Nietzsche, knowing what to say that is truest of
all is the highest understanding of all things permitted for man to
know to share among men. Excluding, of course, a Greek love between
men that hasn't some of the connotations to men, in our age, and by
what we traditionally sanction in holy union, from a reserve they
tended to regard in more direct terms of family as an extensible organ
of state and the politic proper.)