F3-12800CL9D-8GBXL (x2) on an ASROCK Z68 Extreme3 Gen3 - Need Timimg

[Weirdo23]

I am using 2 kits of F3-12800CL9D-8GBXL on an ASROCK Z68 Extreme3 Gen3 motherboard. CPU is an Intel Core i-5 2500K at default speed of 3.3GHz. Wasn't aware that using two kits would cause issues when I made my purchase but now my lot is cast. I've had nothing but problems from the beginning (random crashes and now BSODs). Stumbled across this forum last night and learned that the memory was the issue. Originally I didn't pay attention to the matched pairs when I installed the memory (each pair have sequential serial numbers), but now they are matched in proper banks.

I now understand that I cant use XMP for timing.

I was able to get the system usable with the following settings:
Freq: 1333
tCL: 8
tRCD: 8
tRP: 8
tRAS: 24
CR: 2N

tWR: 10
tRFC: 107
tRRD: 4
tWTR: 5
tRTP: 5

Adjusted DRAM Voltage to 1.552 and VTT voltage to 1.075.

I am curious to find recommending settings that might allow me to get back up to 1600 with these 4 sticks.

Leaving the configuration set to Auto for XMP and just upping the voltage to the levels listed above didn't result in a stable system. But after using the settings above I can get through a memtest86 session running off a boot cd.

Would very much appreciate any assistance available.

Thanks!

[Tradesman]

Make sure you have the latest BIOS, set to stock timings, CR (Command Rate to 2T (or 2N), XMP off (won't work with two sets), freq to 1600, DRAM voltage to 1.55 to start and VCCIO (Memory Controller) Voltage up about .03...and start from there, if stable can experiment with dropping VCCIO by .01 at a time and possibly DRAM voltage a bit (think you'll prob need that + .05 just with having two sets, but maybe not)

[Gamer1st]

I have the same setup in my sons PC so it made more sense to add to this than to start another.
I've had the ASROCK Z68 Extreme3 Gen3 board set up for him for almost a year with two 4gb sticks of F3-12800CL9D-8GBSR2 in it and had no problems.
Unfortunately he spotted a sale on ram at Newegg and bought two more sticks to give him more "zip" for the new rash of power hungry PC titles.
So now I have a system that needs to be tweaked but the Bios has me locked out. The Load XMP settings tab has two choices...
Auto (which defaults to XMP)
and XMP 1.2 profile 1
All the options for timing adjustments are locked to XMP on auto.
Any suggestions?

[Tradesman]

Check an make sure you have the latest BIOS, then enable XMP and select profile 1 (this should allow for changes in individual timings). if problems persist, post up the DRAM timings (base and advanced/secondary, along with system voltages and what CPU you have in there.