SATA Data Cable Length Standard

[Unixlord]

Since all the standard SATA data cable is 45cm I was wondering if there are performance penalties for using longer cables? The standard has got to be there for a reason right?
I have a sata HDD in the top drive cage of my thermaltake armor and a 45cm data cable just barely reaches it while looking extremely untidy and it resists cable management attempts. I know eSATA has a maximum length of 2m but then why the SATA limit?

(Depending on the answer, May be a candidate for the hard drive myths article.)

[empire23]

Well, anything transmitting at such a high speed is bound to be hit with problems as the length of wire gets long. As you go further in length, you get more attenuation (weakening of the signal), you also get more noise on the signal, since a longer cable is a bigger antenna, making the already weak signal more error prone.

Longer cables also produce physical phenomena like phase distortion, skew and so many other things that wreak havoc on the signal. This all generally means that the ECC or Error Correcting Code has to work more and more often to recover or guess what the damaged signal is, this in turn reduces speed, throughput and increases the likelihood of data corruption.

Here's a tip, if you want to use long runs of length limited/sentitive cables, try wrapping the cables in aluminum foil and see if the results are better, as it acts as a shield that reduces all that willy nilly with noise. Also try to reduce the amount of connectors used if you want to make long runs, as each connector causes slight impedence mismatch and has increased resistance.

ESATA IIRC from the white paper and standards can be used at longer lenghts due to it's cable and shield geometry. And the fact it's being used outside the PC, inside the PC, nasty interference from all the other components cut down reliability of transmission heavily.

[Chai]

eSATA and SATA is basically the same thing.

[Unixlord]

Can factory shielded sata cables be purchased? I only need 60cm vs the standard 45cm.

[empire23]

SATA cables already have a thin shield on them. There are some manufacturers like MOLEX, 3M and POMONA that sell special SATA cables for EMI and RFI heavy environments and some are even environmetally shielded. You might be able to find em from other easier to source brands, but i wouldn't know as i haven't really kept up with PC stuff for a long time.

Specialized SATA cables are hard to find and generally hard to buy as well. You might wanna contact Allied Electronics, Mouser or Digikey for free catalogues for faster reference since most electronic suppliers usually sell by parts codes and not descriptions.

[Unixlord]

Lets just assume I have no access to the aforementioned manufacturers.
Would the following perform adequately enough to have no discernible performance drop vs a regular 45cm cable? Akasa SATA

[Chai]

60cm is still below the recommended 100cm I've read somewhere.

[Unixlord]

Can coiling sata cables cause any problems or performance loss? A lot of people do that to standard 45cm cables in order to reduce the length and keep things tidier for HDDs that are in close proximity to the motherboard connectors. I have yet to see any cables shorter than 45cm for sale.

[mikegas]

SATA spec says it 1 meter max cable if not mistaken. As it is serial communication so it more robust to noise and interference. While SAS uses high differential voltage, can go up to 8 meters.

Can get rough idea from here:-

Serial ATA - Wikipedia, the free encyclopedia