According to Drivers and Downloads for my XPS 8500 Win 8, is see this:
Intel Rapid Storage Technology Recommended 3/2/2013 11.1.0.1006, A00
The date is after I bought my system.
However when I run the exe. it claims "This computer contains driver versions newer than the version you are about to instll:
"Intel 7 series/C216 CHipset Family SATA AHCI Controller 11.6.1.1001
SO, is it really an older version?
PS, the Dell email support function seems to be 'temporarily non-functional.'