SATA2 3Gbps和SATA3 6Gbps的数据线是否有区别？

先说结论：

在使用“高品质”SATA数据线的情况下，没有区别。

可以参考SATA-IO的文件：

SATA 6Gbs Fast Just Got Fasterhttps://sata-io.org/system/files/member-downloads/SATA-6Gbs-Fast-Just-Got-Faster_2.pdf

The same cables and connectors used for current SATA implementations can be used to connect SATA 6Gb/s devices. SATA-IO recommends utilizing quality components to ensure data integrity and robust operation at the fast 6Gb/s transfer rate. Cables already at the threshold of 3Gb/s operating margins may experience lower performance than expected at 6Gb/s due to an increased number of resends.

大意为：SATA 6Gbps可以使用与之前相同的线缆和插头。但如果由于线缆品质不好，导致发生了更多的重传， 则实际性能可能会低于预期的6Gbps。

有老外做过两次测试，他选用了若干明确标注为支持SATA3的数据线，以及若干没有特殊标注的普通SATA数据线（SATA2数据线），在相同的硬件平台上测试硬盘的传输速度。两次测试结果均显示，这些SATA数据线之间并没有（有实际意义的）性能差异。

为便于观看，这里附上老外测试的结果截图，原文可以访问下面的链接。

老外的第一次测试（SATA cables: Is there a difference?）：

https://www.pugetsystems.com/labs/articles/SATA-cables-Is-there-a-difference-97/https://www.pugetsystems.com/labs/articles/SATA-cables-Is-there-a-difference-97/老外的第二次测试（SATA 3Gb/s vs. 6Gb/s Cable Performance (Revisited)）：

https://www.pugetsystems.com/labs/articles/SATA-3Gb-s-vs-6Gb-s-Cable-Performance-Revisited-183/https://www.pugetsystems.com/labs/articles/SATA-3Gb-s-vs-6Gb-s-Cable-Performance-Revisited-183/