This took a lot of time and effort, but it was worth it. What I have done is an Eco-Overclock that refined prior iterations of 1T GDM 3600 MHz FCLK=MEMCLK for stability. I had to downclock slightly to 3533 MHz because my prior results were tainted by a setting I didn't know was turned on: Performance Profile – Cinebench. This little shit setting was giving me false positives and negatives throughout my entire OC effort! Removing this actually got my temps under control, but it cost me in my Phoronix Test Suite Scores. Idle latency is 76 ns, which isn't horrible for such a setup.
I retained most of my bandwidth and latency gains relative to XMP. Keep in mind that CXMT C-dies don't like heat, so the eco-overclock proved to be more efficient, especially with 8 ranks clogging my bus and 4 DIMMs producing a lot of heat pockets. I thought an exhaust fan above the DIMMs would be sufficient, but as some of you pointed out, it needed direct air circulation, so I opted for the 2-fan ThermalTake air cooler, and it works like a charm plus is cheap.
It is passing tests and has thrown no WHEA errors after 2 days. Ryzen 9 5900 X is holding cool and steady, so I know I've reduced strain on the IMC: Y-cruncher spikes temps early in each iteration, reaching up to 81 C, but it was holding between 70-72 C. It's worth noting that when playing in UE5, temps were reaching 91 before undervolting this overclock. In the future, I may increase SoC pending an AIO solution.
Lemme know what you think.
Tangential settings:
BankGroupSwap: Disabled
BankGroupSwapAlt: Enabled
SoC LLC: Mode 3
SoC NB LLC: Mode 3
Switching Frequency: 400 KHz
NB Switching Frequency: 400 KHz
Voltages: Absolute lower limits for my rig
SoC: 1.100 V
VDDP: 0.900 V
VDDG CCD: 0.950 V
VDDG IOD: 1.000 V
VDIMM: 1.36 V
Timings
tCL: 16
tRCDRD: 18
tRCDWR: 18
tRP: 18
tRAS: 32
tRC: 54
tRFC: 454
tWR: 20
tRTP: 10
tFAW: 16
tCWL: 16
tWTR_S: 4
tWTR_L:10
tRRD_S: 4
tRRD_L: 8
tRDRDSC_L: 4
tWRWRSC_L: 4
Impedances
ProcODT: 36.9 Ohms (works at 40 as well)
RttWr: 80 Ohms
RttNom: 34 Ohms
RttPark: 120 Ohms
Drive Strengths:
ClkDrvStren: 30 Ohms
AddCmdDrvStren: 40 Ohms
CsOdtDrvStren: 30 Ohms
CkeDrvStren: 30 Ohms