SATA 2 vs. SATA 3 cable

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stone-69

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Oct 25, 2010
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Hi
Building my new PC I've looking at two sets of SATA cables.
One said "SATA 2.0 3 GB/S" and the other said "SATA 3.0 6 GB/s".
But looking at the cables and the connectors they looked quite the same.
So my question is :
Are there any real differencies between a SATA 2 and a SATA 3 cable ?
 
Yes, there is a real difference, it's the data transfer speed. SATA 3 has the potential to double the speed of SATA 2. Like malmental posted, the cables can be used interchangably. Here are the possible scenarios you'll encounter:

1. Device and mobo support SATA 2 - use of a SATA 3 cable will not get you the 6GB/s due to physical limitations of device and mobo.
2.Device and mobo support SATA 3 - use of a SATA 2 cable will not get you the 6GB/s due to physical limitation of the cable.
3. Device supports SATA 3, but mobo supports SATA 2 - using either SATA 2 or 3 cable will result in 3GB/s.
4. Device supports SATA 2, but mobo supports SATA 3 - using either cable will result in 3GB/s.
5. Device and mobo support SATA 3 - use of SATA 2 cable will result in 3GB/s
6. Device and mobo support SATA 3 - using a SATA 3 cable will get you the 6GB/s
 
Indeed, the speed difference is in the interface not the cable. My post above was to clarify to the OP that the cable doesn't matter, as there is a confusion as to what cable to use (meaning there is an apparent choice). My apologies if my explantion made you more confused. I guess it would have helped if I stated this first...
 


But if I was reading the previous post correctly, it is implied that the cable will make a difference:

Device and mobo support SATA 3 - use of SATA 2 cable will result in 3GB/s
 
Yes, I "implied" that because you posted your cables have SATA 2 and 3, respectively. Although the speed is in the interface, I drew out the scenarios for you. I apologize for the confusion. Just know that no matter what the cable shows, the device determines the speed.
 
I didn't make the initial post, but the responses did help me realize that even though the ports are SATA 3, I can still use my SATA 2 gear in the - I was freaking out that I only had 4 SATA 2 ports on my board!
 
The Sata 3 spec has tighter tolerances so it is VERY possible that some cables (that were only tested to the Sata 2 spec) will not meet the Sata 3 spec. What drive/controller and what motherboard you are using can also have some effect on this. To be sure I would ONLY use a cable labelled as Sata 3 if you want to be running at Sata 3 speeds.

This is what the upgrade guide basically says.

Page 5.
http://www.serialata.org/documents/SATA-6-Gbs-The-Path-from-3gbs-to-6gbs.pdf
 
http://www.serialata.org/documents/SATA-6-Gbs-The-Path-from-3gbs-to-6gbs.pdf[/quotemsg]

That is a very useful link. Two key points come from it.

1. A cable which truly met the SATA 2.6 standard would work fine at 6 Giga Bits ( Sata 3.0 ) but one that worked fine at 3 Giga Bits but did not really meet the 2.6 standard might fail at 6 Giga Bytes.

2. Longer SATA 2.6 cables approaching the length limit of the standard are more likely not to work at 6 Giga Bytes than SATA 2.6 cables half as long.


 



I agree. Some cheap cables could not work. This is a quote from the document:

Problems may be related to the use of cables made from marginal materials that
perform at the edges of SATA 3Gb/s tolerances, which could become a failure point at the faster 6Gb/s signal rates. SATAIO therefore recommends that only high quality
cables and connectors be utilized for SATA 6Gb/s.


 
This message comes from Serial ATA site.
9: Does SATA 6Gb/s require different connectors and cables to support the higher
transfer speed?
A9: The same cables and connectors used for current SATA 1.5 and SATA 3.0 Gb/s
implementations can be used to connect SATA 6Gb/s devices, although SATA-IO recommends
quality components be selected to ensure data integrity and robust operation at the faster SATA
6Gb/s transfer rate. Keeping the existing SATA connector form factor enables SATA 6Gb/s to
be designed into the same cost-conscious hardware architectures while minimizing
infrastructure changes.


It would be nice if someone could test a sata II and sata III cables with sata III hardware and see if there is any advantage.
 
All the doubts around the marketing hype created by so-called SATA 3.0 Cables should be cleared after reading this:

Is Your SATA Cable Slowing Down Your Data Transfers? Max PC Investigates - http://www.maximumpc.com/article/fe..._down_your_data_transfers_max_pc_investigates

What did they find? - Quote from the article below:

Let’s first say that when we started this, we were absolutely sure we’d see a difference. Afterall, moving to an authentic SATA 6Gb/s cable cleared up our problems the first time right? Wrong. As we worked our way through the first few cables, we began to realize that the SATA I/O did its work when it first put together the Serial ATA spec for cables. There is virtually no difference between a brand-new SATA 6Gb/s marked cable made this year and one produced nearly eight years ago as far as performance goes. Expensive cable, cheap cable; long cable, short cable—none of it seemingly made a real difference. If anything, the minor variances in performance can be attributed to variances in the benchmark or the SSD.
 
The easy way to say this is your connection speed will be the lessor of the device or the cable.

If you want a 6GB/s connection you need a III device AND cable. If you want to make any use of it, you'll need a RAID or SSSD, because no single drive will saturate a 3GB/s connection.
 

Sorry, but to be honest, that's a rather stupid conclusion based on everything discussed here.
 
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