General C-die overclocking, Rocket Lake IMC


New member
Nov 20, 2021
@citay and anyone else who has fun with ram OC

This is on a kit of cheapo Kingston Fury 2 x 16gb rated for 3200 cl 16. Unfortunately Kingston regularly overwrites the SPD on its ICs for its bargain bin SKUs, meaning that you essentially cannot identify the die they use. I took off one of the heatspreaders and it said Kingston on the die... go figure.

Anyway, after doing some quick voltage scaling testing last night, I determined it was C-die (5WC), which makes sense given the price I paid for this. I then did some quick and dirty exploration of how far you can push this dual rank kit on a 11400 + B560 combo.

Some quick notes from my experience with the RKL IMC. Firstly, VCCSA seems to be the key to booting. If you jam enough VCCSA into the IMC, even the craziest frequency/primaries will boot. VCCIO2, on the other hand, seems to be more for actual memory stability. With insufficient VCCIO2, red-hot OCs will start to error out, but if you jam enough in, they will run stably for a while, enough to pass 3 hours of TM5 absolut.

The kit will boot at 3733 19-21-21-40 auto with SA 1.6 and VCCIO2 1.6, and benches pretty well in y-cruncher. Stability wise, at that level of VCCIO2 voltage, it passes TM5 absolut. Obviously those voltages are not for daily driving, but if I lower SA below 1.55 it will simply not boot, so that's that.

I attempted to boot it at 3600-18-20-20-38, the standard XMP speeds, but for some reason my IMC has a "hole" at 3600 cl 18 and no combination of primaries or voltages will boot. 3600 17-20-20-37 will boot and bench happily with SA 1.4 and VCCIO2 1.55, but that's too high for daily comfort.

I eventually settled on 3333 16-19-19-35 with SA 1.22 and VCCIO2 1.25 as a daily, with all secondaries and tertiaries set to auto. The board seems to do a decent job of memory training at these conservative levels. None of the secondaries or tertiaries drifted in 10 trainings.

My next step is to tighten secondaries somewhat - nothing too aggressive, probably just tRRDS/L to 4/6, tFAW to 16, and tRFC to be 567 = 340 ns. IMLC says my latency is around the 51 ns mark currently, which isn't too bad.