Let's say I have the fastest reading SDD, which has a 2 gb/s read speed. However, nowadays the standard for SATA transfer rate is 6 gb/s. Therefore, wouldn't the speed of the read/write make make the data transfer only as good as the HDD/SDD? This would mean that the standard 6 gb/s is unnecessary. Or am I wrong?
True, the data transfer rate is only as good as the HDD/SSD but if you have a SATA III drive connected to a SATA III port you will see a significant difference in the transfer rate. As many newer SSDs and HDDs are SATA III I would argue that the standard 6 gb/s is quite useful but then again it all depends on the user. If you are satisfied with the transfer rate then there is no need to change/upgrade. Personally, I like the faster read/write speeds as I write, read and copy large files (video and photo editing).