So in this case the limitation is my hard disk speed which is 5.7 rating

Intel's "Rapid Start Technology" speeds up the resume time for a laptop coming out of hibernation state compared to the standard Windows hibernation mode because the system's memory contents are saved to the speedy SSD instead of the hard disk.

And their "Smart Response Technology" caches frequently used files, data, and applications on the same SSD drive for faster access instead of going to the hard disk each time.

Intel's "Rapid Start Technology" speeds up the resume time for a laptop coming out of hibernation state compared to the standard Windows hibernation mode because the system's memory contents are saved to the speedy SSD instead of the hard disk.

use on my thinkpad x240 as main hard disk

And if your computer is equipped with an SSD using Intel's "Smart Response Technology", it may retrieve the data from the speedy SSD cache instead of reading from the slower disk