Does someone can simply explain me what is NCQ?
NCQ = Native Command Queuing
And pretty much does exactly what it says. It allows for commands to get stored up, sorts what commands are more important, retrieves the data for them and moves on.
Here is a whitepaper on it www.seagate.com/docs/pdf/whitepaper/D2c_tech_paper_intc-stx_sata_ncq.pdf