SSD for SATA 3 or SATA 2?

Question

Solid State Drives

Hello everyone, my motherboard has 4 SATA inputs: 3 SATA 2 and 1 SATA 3.
There are two SSDs: C 120GB (only with the system and applications, the installation path of which cannot be selected) and D 240GB (it stores all the programs on which I I am writing the code, and all the data in general)
The essence of my question is: Which of the SSDs would be rational to plug into SATA 3?

Answer 1

Absolutely no difference, even synthetic tests will not give noticeable differences
ps tests will give a difference in linear reading, sata2 no more than ~ 300 megabytes / second (3gigabit / s) sata3 give speeds up to 600mb / s (6Gb / s), some ssd even cheap ones can give reading up to 400MB / s,
but for the layman it makes absolutely no difference

Answer 2

System in SATA3, file in SATA2 - all the same, you access the system more often and it is any more loaded than D

Answer 3

The one on which the system is in SATA2