F3-12800CL9D-4GBRL x 2 & Asus P7P55D

[Titang]

I checked the voltages and each stick separately, nothing wrong. I really don't get why it stopped working suddenly. Any other idea?

[Tradesman]

Yes try tRFC up to 110, and CPU (vCore) voltage to 1.27

[Titang]

I tried your settings right after your message and it has been working so far. Hope it will continue but thank you very much for your help, I feel like everything possible is being tried, thanks to you.

[Tradesman]

Glad I could help, Enjoy!

[Titang]

4 months later, finally, it still doesn't work. I haven't used my computer that much these last months, that is why I haven't posted earlier.
I only use 4 Go and every things is fine, keeping the other set for later. If anyone has another idea, I ll try it but I think my motherboard is definitely incompatible with two sets like I have. Thanks for the support anyway

[Xenofin]

I had earlier the same RAM and two separate kits and the same motherboard as you have. To get these sticks to work I had to raise memory voltage up to 1.65V (nominal 1.6V IIRC) for DDR1600. My CPU was overclocked (i7-860) and I had to raise also this voltage a notch (0.005-0.008V) compared to situation where I had only two sticks of RAM. My OC for CPU was 3.92GHz requiring 1.35V for two sticks and 1.36 for 4 sticks. Also note that you should lower NorthBridge (i.e. memory controller) speed for memory in Bios (use CPU-Z to observe real NB speed). There should be two options to select - select the lower setting. This gives your memory controller more room to operate and does not affect on performance much. Keep CR as 2T with their rated speed. I got these four sticks to operate with 1T but only when I relaxed other timings thus making this change not worthy.

At the moment these sticks are installed in another PC with i5-2500K CPU and P68 based motherboard and they work without problems at their rated speed (CPU is overclocked) with 1.65V.

[Titang]

I raised the memory voltage and CPU voltage. Did not find the setting for the memory controller in the bios and the CR (alreaydy set to 2T anyway. Seems to work so far (24hours). We'll see. Thanks for your help

[Xenofin]

OK, good for you. IIRC in BIOS of this board it is QPI Frequency in AI Tweaker Menu. I remember selecting the lower value from the selection offered.