aerai :
The SATA-III connection is a 6.0 Gb/s (small b) which is bits. When converted into bytes (big B) there is a ratio of 8 bits to a byte. So:
6 Gb = 6000 Mb = 750MB (roughly speaking)
The previous standard, SATA-II was 3.0 Gb/s which is about 375 MB/s and so not capable of running the faster SSDs. I think there is a bit of variance in the actual transfer rate though which means they would likely be slower than those I have used as examples.
You are right
technically with regards to your math. 6Gb/s = ~750MB/s.
But if the conversation is regarding SATA speeds then you are incorrect.
The way SATA ports are designed the maximum data bandwidth of a SATA 3.0 (6Gb/s) port is ~600MB/s, not ~750MB/s.
The difference is due to protocol overhead (10b/8b coding with 8 bits to 1 byte). Don’t ask me to explain what it means, it’s over my head. LOL
The maximum data bandwidth of a SATA 2.0 (3Gb/s) port is ~300MB/s, not ~375MB/s.
The maximum data bandwidth of a SATA 1.0 (1.5Gb/s) port is ~150MB/s.