CPU-Z showed Ram Speed @798 AKA that is 800 MHz. Cpu-z should have also shown that it was in daul channel mode.
Hense 800 x 2 = 1600. SO Ram is running at the correct speed.
HDD (Your SSD), is a Agility III SSD is a POOR excuse for a SATA III SSD (sorry to be blunt, and yes it is still wayyyyy faster than a HDD - Also Yes I have a Pair of them).
Reason: It uses Asynchronous NAND Cells and as shown in one review it does NOT perform any faster on a SATA III port than on a SATA II port - also verified this with my Agility III. Typically this drive only gets aout a 7.2->7.6 for WEI after a short period of Usage. Your 7.9 was based on a 240 gig (vs the 120 gig drive) and probably done right after install. Bottom Line here is be HAPPY with your 7.7 NOT caused by adding RAM
WEI 7.9 is Max for win7 and should only be abtained by the "higher end" SSDs using Toggle NAND and Synchronous NAND chips that do benifit from SATA III.