Help getting 1600 stable

[LBear]

Here are my specs (stable)...

CPU: Phenom II x3 720 @ 3.5 Ghz
RAM: G.skill Ripjaws 4gb @ 1333
MB: MSI N980-G65
PSU: Antec 1000w
CPU-NB @ 2600
HT link @ 2000

In the bios i change the memory divider to 1/4 for 1600 and i set the timings manually to 9-9-9-24 2T at auto(1.5v). I cant pass IBT(Intel Burn Test) at these voltages and in memtest i get errors on the first pass on test #8. Now in order for me to pass IBT i had bump the voltage to 1.6v, also by doing this in memtest i can complete two full passes but on the 3rd or 4th time around i get errors again ONLY on test #8. So either i have to bump the voltage higher than 1.6 or it could be my processor cause its a C2 and not a C3. If its my processor im trying to rule the ram out. Can i take the voltage up higher that 1.6v and be safe? Whats safe voltage for this ram? The numbers go yellow at 1.61v and go red at 1.71v. Any advice would be great, thanks.

[Tradesman]

Which ripjaws do you have, I'm sort of assuming you have the F3-12800CL9D-4GBRL, if so with the C2 CPU at 3.5, you may want to run the DRAM at 1.55-1.6 (safe), and try raising the tRFC. May also have to loosen the timings to 9-9-9-27 2T or 9-10-10-29 2T (possibly even to CL10.

Might try these options and if troubles continue, would help if you could post your BIOS settings.

[LBear]

yes im using the F3-12800CL9D-4GBRL RAM, I will try the timings u mentioned and run memtest, here are my current bios setting. I know nothing about the tRFC,u have any clue on what to change them to?