Upper Spec Limit on Length of SATA Cable?

[BonzaiDuck]

This had never been a noticeable problem for me, and since you could always get straight-to-straight (or angle combinations) in 1m lengths, it never had occurred to me.

I had to use a 1m internal cable to a front-panel eSATA port. The eSATA-to-eSATA cable connected to any of my external drives is also 1m.

I've had a flaky experience with a Samsung ODD (DVD/RW -- 4 months old) in a reliable eSATA box with probably another 1 ft of cable between the back of the box and the device inside.

Never had problems with those boxes when they contained HDDs. I was able to get the Samsung to work, and I'd configured the port in BIOS to be "hot-plug enabled." But I almost have to boot twice to get the motherboard to recognize the ODD. There seems to be always a red-bang Event Log item that appears just after bootup when the ODD is powered off, with -- I think -- "Source:" as CDROM.

Somehow I think it would be better to get a USB ODD. However, I still want to know how long you can go with SATA cables with connections. I've found front-panel 5.25" products which offer two 2.5" hot-swap bays with a slim ODD above the bays in a 5.25" Icy-Dock Item. That would give me an ODD-and burner without relying on an external SATA ODD. Maybe I'll have to get short eSATA-to-eSATA cables to use the external box. I just don't have room in the case for both a hot-swap bay and an ODD, unless the hotswap is 2.5" and the ODD is "slim" form-factor. the IcyDock device provides me with the two functions in half the bays.

So . .. . what's the spec SATA length limit?

Any other recommendations for a single 5.25" device providing hot-swap, optical and USB?

Any advice on the need to order shorter e-SATA-to-eSATA cables?

 

[jimbob200521]

A quick google search shows 3.3 feet maximum SATA cable length.

http://lmgtfy.com/?q=sata+cable+length+limit

 

[corkyg]

3,3 ft = 39.6 inches. I meter = 39.37 inches. Ergo, 1 meter is within, but almost at the length limit for a SATA cable.

 

[dave_the_nerd]

3,3 ft = 39.6 inches. I meter = 39.37 inches. Ergo, 1 meter is within, but almost at the length limit for a SATA cable.

The "1m" and "0.5m" cables in the lab at work vary +/- 15cm or so, depending on manufacturer.

Which is infuriating.

 

[corkyg]

The "1m" and "0.5m" cables in the lab at work vary +/- 15cm or so, depending on manufacturer. Which is infuriating.

Agree. And that is why some issues can be solved by changing cables. Cables shorter than marked can be OK is many cases, but a cable should never exceed the maximum specified length of a class or mode.

 

[BonzaiDuck]

Agree. And that is why some issues can be solved by changing cables. Cables shorter than marked can be OK is many cases, but a cable should never exceed the maximum specified length of a class or mode.

Well, I haven't had any problems with HDDs in external boxes, but then I haven't played with them frequently enough to be absolutely sure.

To make the connection between my mobo SATA port and a top/front-panel eSATA port, I need a 3-foot-long cable. And I'm using a 3'-long cable from the front of the case to the external box.

That's six feet. The only thing I COULD do at this point with it is to find a short 1' eSATA-to-eSATA cable, and then I may have shortened the connection to 4'.

I thought I saw a 6'-long SATA cable while I was window-shopping the online resellers. But that's outside the spec, so it would seem . . . impossible.

For eSATA from the rear of your tower case, you'd use an 18" controller-to-PCI cable with eSATA port on the PCI slot-plate. And for your eSATA-to-eSATA connection, the most common cable length is -- again -- 3ft or approximately 1meter.

Anyway, for the difficult ODD -- regular size ~2"x5.25"x [depth/length] -- I found an ICY DOCK bay device which provides hot-swap for 2x 2.5" HDD/SSDs, and room for a slim-form-factor or laptop-style ODD.

And I'll probably avoid using the eSATA connections unless absolutely essential for something . . . .

 

[corkyg]

If you use a SATA power extender cable, you can possibly add 12 more inches to the reach.

 

[BonzaiDuck]

If you use a SATA power extender cable, you can possibly add 12 more inches to the reach.

Can you point to any of such a device or adapter at some reseller web-site?

I find the problem "interesting." All the computer cases I have in my use and inventory include front-panel eSATA except for my old Stacker 830 -- which I am renovating and where this issue pops up. They all come fitted with an SATA internal cable from mobo to front-panel that is somewhere between 24" and 36" long. This leaves it to the user to select an eSATA-to-eSATA cable of some practical length.

Or did I miss something -- how critical is cable length to proper operation with an SATA-II (or III) device connected to an SATA-II port? Or is the cable spec more critical to something like an "external" SSD operating at maybe 2+x the sustained throughput you would expect from ANY HDD?

 

[corkyg]

Can you point to any of such a device or adapter at some reseller web-site? ...

Not without spamming. Just Google "SATA power extender cable."

Yes, anything beyond specified length seems to be called into question. I find it hard to pin down precisely. Perhaps it one of those things that after the max length is passed, flakiness can appear and increases with the added distance.

 

[Micrornd]

You're should be looking at the total length from MB port to device.
That includes internal and external cables.
You'll find that exceeding that 1m length is asking for errors, slowdowns, not recognizing the device sometimes or at all.
Trust me, I've tried it with the best cables and anything over 1m (total) ends up being a crap shoot (even with eSATA)

 

[BonzaiDuck]

You're should be looking at the total length from MB port to device.
That includes internal and external cables.
You'll find that exceeding that 1m length is asking for errors, slowdowns, not recognizing the device sometimes or at all.
Trust me, I've tried it with the best cables and anything over 1m (total) ends up being a crap shoot (even with eSATA)

So it would seem that a front-panel eSATA port is just asking for trouble, unless the total cable length is <= 1m.

Good thing for me that I don't depend a lot on using such a setup with any frequency. But I'm rethinking the "custom" eSATA ports I installed in the front of my Stacker 830 "resurrection." I'd do better just to replace them with a double USB3 plug. Or I could simply leave the eSATAs unconnected and call it a day.

Moral of the story: if you can't meet the 1M limit, then better to put a 1M cable in an eSATA port at the rear I/O of you have any. I'm still a bit puzzled though. Cases featured with front-panel eSATA came ready with an internal cable of at least 2 feet.

I've never been all that goo-gah over external devices. Different priority for a laptop user -- I can see that.

 

[Johnny Lucky]

I just want to mention that the maximum length of eSATA cables is 2 meters. If you have an eSATA port on the rear panel of the motherboard, then you could simply connect to that port instead of using a combination of eSATA and SATA cables.

 

[corkyg]

That is correct. eSATA = 2 meters; SATA = 1 meter

 

[BonzaiDuck]

Johnny Lucky and corkyg inform us that the length of an eSATA cable can be 2 meters. And Johnny says I can connect such a cable (or shorter) to the rear I/O eSATA port at the motherboard.

But I'm puzzled as to how this guides me about using a 1 m internal SATA cable from controller-port to SATA-eSATA converter plug, and using another 1m eSATA cable to connect the external device. I have a 2m connection from mobo to device, but half of it is half the cable-length limit of eSATA.

It's an "apples and oranges" that has to be somehow measurable against the simple cable-length standard. If I can use a 1m SATA together with a 1m eSATA, how does that differ -- or how much does it differ -- from running a 2m eSATA from the motherboard?

Incidentally. I think I started this thread in mentioning that I had a f***y behaving ATAPI external eSATA box with ODD. I am beginning to suspect that I may not have had the "hot plug" feature enabled in BIOS for that port in the BIOS list of SATA ports. Since my memory of it seems a bit flaky also at the moment, I think that was the reason that I could shut down the system, raise it up and it would recognize the connected external box if turned on. If I tried to turn it on in Windows desktop -- no cigar. If I rebooted -- maybe, maybe not.

Listen. Think about it. Without knowing anything more than we've discussed here, I mentioned that cases come with 1m internal SATA-to-eSATA for the front-panel port. You would then think that this anticipates someone using an eSATA-to-eSATA cable of a meter or less?

I mean -- the ultimate concern here is the integrity of the data and the external device. What else do we need to know to feel comfortable about that?