maximum length of SATA cable

G

Gregory Abbey

What's the maximum length of a SATA cable?

know of any `four device' SATA adapters for RAID?
That is two RAID-0 pairs?

-G
 
G

Gregory Abbey


Thank you.. was all set to build a four-disk array of two IDE pairs
(two RAID-0 drives) on a single FT100 TX2 card.. but the 18" cable
length limit prevented it. Have been asking around for months and
years if going over the 18" length (to 24") is ok? for overlength IDE
ribbons with both MST and SLV devices connected. The answer is
always.. NO - it violates the spec .. except for the vendors who want
to sell cables.

Still have not built the file server with four ATA-100 drives on the
TX2 card that requires 24" ribbons.


-Gregory
 
T

Toshi1873

Thank you.. was all set to build a four-disk array of two IDE pairs
(two RAID-0 drives) on a single FT100 TX2 card.. but the 18" cable
length limit prevented it. Have been asking around for months and
years if going over the 18" length (to 24") is ok? for overlength IDE
ribbons with both MST and SLV devices connected. The answer is
always.. NO - it violates the spec .. except for the vendors who want
to sell cables.

Still have not built the file server with four ATA-100 drives on the
TX2 card that requires 24" ribbons.

Solution: Get a better case.

I have a 6-port Promise RAID card (PATA), and in a full-
tower case it was a real pain to get those cables up
into the upper drive bays.

Instead, look at cases like the Antec p160, Antec
Sonata, or Antec 3700-something where there are (4)
drive bays down at the motherboard in the lower-half of
the case. (I own 3 p160 cases and a single Sonata
case.)

In addition, they have a spot to install a 120mm fan so
that you can pull air in from the front, and it will
flow directly over those internal hard drive bays.
 
K

kony

Thank you.. was all set to build a four-disk array of two IDE pairs
(two RAID-0 drives) on a single FT100 TX2 card.. but the 18" cable
length limit prevented it. Have been asking around for months and
years if going over the 18" length (to 24") is ok? for overlength IDE
ribbons with both MST and SLV devices connected. The answer is
always.. NO - it violates the spec .. except for the vendors who want
to sell cables.

Still have not built the file server with four ATA-100 drives on the
TX2 card that requires 24" ribbons.

I've done it several times using rounded cables with
twisted-pair construction (any decent cable will be built
this way). Use shortest cable possible. It will also help
that you're running in ATA100 instead of ATA133 mode.
 
G

Gregory Abbey

I've done it several times using rounded cables with
twisted-pair construction (any decent cable will be built
this way). Use shortest cable possible. It will also help
that you're running in ATA100 instead of ATA133 mode.

thanks.. I've read a lot about the round TP cables.. and agreed it
helps with ATA100 vs 133. The thing is.. what about FOUR drives on the
cables.. the 18" limit.. the position of the SLV device on the cable..
and of course.. having two RAID-0 pairs.. one pair MSTR and the other
pair SLV configuration. That is the issue. I'd not hesitate as much if
it were simply a drive at the far end of each ribbon.
 
G

Gregory Abbey

Solution: Get a better case.

The case I bought was for the Linux gateway.. that is before
inexpensive NAT devices came along. The TOWER is a mighty
SuperMicro which has up to nine fans. Try out a google search for
SuperMicro Case or SuperMicro Tower and you'll see these awesome
(yet expensive) boxes.
I have a 6-port Promise RAID card (PATA), and in a full-
tower case it was a real pain to get those cables up
into the upper drive bays.

In the case of the SuperMicro 500.. it was impossible for the 18"
cables to reach the four upper 5" bays.
Instead, look at cases like the Antec p160, Antec
Sonata, or Antec 3700-something where there are (4)
drive bays down at the motherboard in the lower-half of
the case. (I own 3 p160 cases and a single Sonata
case.)

In addition, they have a spot to install a 120mm fan so
that you can pull air in from the front, and it will
flow directly over those internal hard drive bays.

Yep.. it had side mounted fans for SCSI drives. : )
 
K

kony

thanks.. I've read a lot about the round TP cables.. and agreed it
helps with ATA100 vs 133. The thing is.. what about FOUR drives on the
cables.. the 18" limit.. the position of the SLV device on the cable..
and of course.. having two RAID-0 pairs.. one pair MSTR and the other
pair SLV configuration. That is the issue. I'd not hesitate as much if
it were simply a drive at the far end of each ribbon.

Well, since it's PATA, there's two drives per cable so all
you can do is place the slave as far down in the chassis as
possible, in an effort to keep cable shorter. Unfortunately
I don't know where one can buy long cables that have both
connectors closely spaced at the end as would be optimal for
a pair of drives at the top of a case. There probably are
such cables out there, but if possible I prefer putting raid
arrays in the bottom, adding another bay if possible.
 
T

Toshi1873

The case I bought was for the Linux gateway.. that is before
inexpensive NAT devices came along. The TOWER is a mighty
SuperMicro which has up to nine fans. Try out a google search for
SuperMicro Case or SuperMicro Tower and you'll see these awesome
(yet expensive) boxes.

I owned 3 of the SuperMicro full-tower cases (750S or
something), they were my preferred case for a while. I
much prefer the newer case design of the Antec p160
except for the issue with motherboard size limitations.

Never installed fans along side of the drives (moot
point since it was too difficult to stretch the 18"
cables). Instead, I used individual bay coolers.

The best drive-bay cooler I have is a no-name unit that
holds up to (3) 3.5" disks and takes up two 5.25" slots.
It has a single 70mm or 80mm fan to pull air in across
the drives. The larger fan is much quieter then the
usual battery of 2x40mm or 3x40mm fans on individual bay
coolers. I never filled it up with 3 drives though,
instead I just put two drives in the cooler and left an
air gap between the drives for air flow.

I think PC Power & Cooling now makes a 2-bay, 3-drive
unit.
 

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