Question: Regarding SATA Cables?

[Blazing Bolt]

Ok so you all know the little red SATA cables that come with most
motherboards now. I see a lot of places selling SATA cables labeled
as SATA II cables and some that only say SATA.

My question is this; can those little red cables that come with most
mobo's which seem to be labeled as SATA run an SATA II drive at full
speed? Can the cable really make a difference? I searched all over
for a conclusive answer but have yet to find one, so I figured this is
the place to ask…

Thank in advance.

 

[Paul]

Ok so you all know the little red SATA cables that come with most
motherboards now. I see a lot of places selling SATA cables labeled
as SATA II cables and some that only say SATA.

My question is this; can those little red cables that come with most
mobo's which seem to be labeled as SATA run an SATA II drive at full
speed? Can the cable really make a difference? I searched all over
for a conclusive answer but have yet to find one, so I figured this is
the place to ask…

Thank in advance.

Section 6.1.4 PDF page 14.
http://web.archive.org/web/20050330...ialata.org/docs/PHYii Spec Rev 1_0 052604.pdf

"The Gen2i Electrical Specification aims at the desktop
and mobile market for Serial ATA driuves. The primary
consideration in this application is to maintain complete
backwards compatibility with existing Serial ATA 1.0a
devices."

So, yes, for internal cabling, the same cable is supposed to work
for both.

Be careful not to kink or bend the cable. If you've bent it, consider
replacing it. A bend at those speeds, can cause a reflection and
data errors. Similarly, pinching the cables is not recommended (like
using nylon ties to tightly strap the cables down).

Paul

 

[ToolPackinMama]

Be careful not to kink or bend the cable. If you've bent it, consider
replacing it. A bend at those speeds, can cause a reflection and
data errors. Similarly, pinching the cables is not recommended (like
using nylon ties to tightly strap the cables down).

That's interesting. I never heard that before.

 

[Paul]

That's interesting. I never heard that before.

There has been at least one person who noted their problems
were cured, once a bent cable was replaced. At these speeds,
bending a conductor, changes the cross section, and changes
the impedance. The same would apply, to changing the position
of a shield, or the properties of the insulation.

http://www.wirelessforums.org/alt-comp-hardware/sata-cables-2620.html
http://forums.cabling-design.com/Re-SATA-cables-article6870-58.htm

In PCB design, we're told to be careful how corners are made
on copper tracks. Using a radius (a curve), keeps a relatively
constant width. Placing a 90 degree angle in a copper track,
means there is a tiny section of track which is SQRT(2)*W wide.
And it was someone's considered opinion, that the effect should
be worried about at the 1Gbit/sec rate or higher.

Paul

 

[Rod Speed]

ToolPackinMama wrote

There has been at least one person who noted their problems
were cured, once a bent cable was replaced. At these speeds,
bending a conductor, changes the cross section,

No it doesnt. And neither does using a tie to constrain it either.

and changes the impedance.

Not necessarily, and it isnt a constant impedance system anyway.

The same would apply, to changing the position
of a shield, or the properties of the insulation.

http://www.wirelessforums.org/alt-comp-hardware/sata-cables-2620.html
http://forums.cabling-design.com/Re-SATA-cables-article6870-58.htm

What matters is what the sata standard says, not this sort of pontification.

In PCB design, we're told to be careful how corners are made
on copper tracks. Using a radius (a curve), keeps a relatively
constant width. Placing a 90 degree angle in a copper track,
means there is a tiny section of track which is SQRT(2)*W wide.

Different matter entirely to a cable and stuff like sata and cat5 and cat6 etc.

 

[Paul]

No it doesnt. And neither does using a tie to constrain it either.


Not necessarily, and it isnt a constant impedance system anyway.



What matters is what the sata standard says, not this sort of pontification.


Different matter entirely to a cable and stuff like sata and cat5 and cat6 etc.

2.6MB download. PDF page 296.
http://web.archive.org/web/20030213....org/collateral/zipdownloads/serialata10a.ZIP

"Electrical Impedance: 100 +/- 5 ? (differential)
Capacitance: 42 pf/M nominal
Prop delay: 4.25 ns/M
nominal Skew (within pair): TBD
(TDT method, drains gounded) (differential 50%-50%, Tektronix 11801,
SD-24/SD-26 sampling heads)
Attenuation (nominal): TBD db/M @ 4.5 GHz

Physical
(2) shielded pairs 26 AWG solid tinned copper
0.0435 nom diameter foam polyolefin, white
Parallel pair with (2) drains, 28 AWG solid tinned copper
0.001 aluminized polyester, foil in, 0.035 inch min overlap
Blue typical longitudinal wrap, heat sealed

Jacket: 0.020 nom wall PVC, red
All dimensions are inches unless otherwise noted

Figure 76 – Cable construction example"

The 100 ohms plus/minus 5 ohms differential, is an impedance spec.
A constant impedance spec.

The 0.001 aluminized polyester plus drain wires, function as a shield.

There is a picture of the cross section of the cable, on page 296.

The above specification is incomplete, because the real version of the spec
costs money. It's a lot cheaper than I expected.

https://www.sata-io.org/secure/spec_download.asp

Paul

 

[Rod Speed]

Rod Speed wrote

2.6MB download. PDF page 296.
http://web.archive.org/web/20030213....org/collateral/zipdownloads/serialata10a.ZIP

I've already got the standard.

"Electrical Impedance: 100 +/- 5 ? (differential)
Capacitance: 42 pf/M nominal
Prop delay: 4.25 ns/M
nominal Skew (within pair): TBD
(TDT method, drains gounded) (differential 50%-50%, Tektronix
11801, SD-24/SD-26 sampling heads)
Attenuation (nominal): TBD db/M @ 4.5 GHz

Physical
(2) shielded pairs 26 AWG solid tinned copper
0.0435 nom diameter foam polyolefin, white
Parallel pair with (2) drains, 28 AWG solid tinned copper
0.001 aluminized polyester, foil in, 0.035 inch min overlap
Blue typical longitudinal wrap, heat sealed

Jacket: 0.020 nom wall PVC, red
All dimensions are inches unless otherwise noted

Figure 76 - Cable construction example"

The 100 ohms plus/minus 5 ohms differential, is an impedance spec.
A constant impedance spec.

Pity that you wont get anything like that variation with
a bend or using a tie to constrain the cable in spades.

The 0.001 aluminized polyester plus drain wires, function as a shield.

There is a picture of the cross section of the cable, on page 296.

The above specification is incomplete, because the real version of the spec costs money. It's a
lot cheaper than I expected.

https://www.sata-io.org/secure/spec_download.asp

No news to me.

 

[OSbandito]

2.6MB download. PDF page 296.
http://web.archive.org/web/20030213....org/collateral/zipdownloads/serialata10a.ZIP


The 100 ohms plus/minus 5 ohms differential, is an impedance spec.
A constant impedance spec.

The 0.001 aluminized polyester plus drain wires, function as a shield.

There is a picture of the cross section of the cable, on page 296.

The above specification is incomplete, because the real version of the spec
costs money. It's a lot cheaper than I expected.

https://www.sata-io.org/secure/spec_download.asp

Paul

Some of the argument above is irrelevant, since anyone pure enough
to buy top-quality cables would never constrict the cable in ANY way.
Such an act would require burning at the stake. Misereatur tui
omnipotens Deus.

 

[Blazing Bolt]

Hey thanks for the info.. I never knew that about zip ties or
bending...

 

[Richard Adams]

Ok so you all know the little red SATA cables that come with most
motherboards now. I see a lot of places selling SATA cables labeled
as SATA II cables and some that only say SATA.

My question is this; can those little red cables that come with most
mobo's which seem to be labeled as SATA run an SATA II drive at full
speed? Can the cable really make a difference? I searched all over
for a conclusive answer but have yet to find one, so I figured this is
the place to ask...

Thank in advance.

Over the weekend I built a PC for a friend. The SATA cables which came
with the mobo seem to be flaky. These came with an ASUS SLI something
something board, I don't have the box with me atm. Drive formats were
freezing until I found the SATA cables on the back of the 250GB Seagate
Barracuda drives had some play to them.

I'm curious if anyone has a recommendation on some very good cables.