Aurora R4: newly installed SSD only running at G2 / SATA300 - how can I 'persuade' the SATA controller to run at G3 /SATA600?

Good evening.  I was a little undecided on where to post this, but I believe this to be the right location.

I have just replaced the main drive in my Alienware Aurora R4 with a SanDisk Extreme Pro SSD... working perfectly (and pretty fast).  I have carried out a clean build of Windows 10 Pro (x64), upgraded to the very latest version.  I am not using RAID.

The SDD is correctly housed and connected in the SATA01 location.

This Aurora R4 has the 'Dell', well actually 'Intel' Patsburg 6 Port SATA AHCI Controller (Revision A7), capable of supporting G3 / SATA600.  However, both DVD drives are running at G1 / SATA150 and all four disk drives are running at G2 / SATA300.

I have the latest Intel Rapid Storage Technology driver, which confirms a SATA transfer rate of 3 Gb/s for my SSD (and for the other three HDD's).

How can I persuade the computer that I want to optimise the performance of my SanDisk Extreme Pro SSD, by having the transfer rate running at G3 / SATA600 ?

I have trawled through a library's worth of web pages, but not found a solution.  I had rather hoped that it would be a BIOS issue (latest installed) or a SATA Controller firmware matter, but that does not seem to be the case.  The Intel Rapid Storage Technology driver allows no fiddling, so I have drawn a blank there.

Any knowledge-based advice would be warmly received... particularly if you have an Aurora R4 that is running an SSD at G3 / SATA600!!