CPU Benchmark Dropped 15% After OCing Memory

[Notime4games]

Hi, I followed DRAM Calculator (memory settings from Thaiphoon) yesterday and tweaked my memory from 16-18-18-18-38 at 3600mhz to 15-17-18-18-38 at 3733mhz (1.42 DDR voltage, 1.1 SoC voltage) with Infinity Fabric 1-1 with memory at 1866mhz. All runs smoothly, did a few hours of memory stress tests with zero errors. However, I ran a CPU benchmark using passmark and my score dropped from 33,350 to 29,000 (before and after memory overclock). I ran it a couple times with similar results, and just reverted my memory to base XMP timings and frequency and the CPU benchmark result went right back up to 33,350. Any idea what could be causing the CPU performance to drop when memory timings and frequency are improved? Note that I disabled Power Down Mode and Gear Down Mode when memory was overclocked. CPU is at stock settings.


My system:

Ryzen 3900XT (stock settings)

NZXT Kraken x63 (CPU temps in low 30's c idle and 60's at load, occasionally coming up into the 70s for a couple second)

Crucial Ballistix Gaming memory: 2x8gb (3600mhz CL 16-18-18-38 stock, Micron E die)

Gigabyte Aorus Elite x570 (latest F20 bios)

Sabrent Rocket PCIE 4 NVME SSD

 

[Ross Thomson]

probably because your memory OC is throwing up errors.

are you using DRAM calculator mem test to check the OC?

I would suggest changing the main timings back to 16-18-18-38 and test that @ 3733. Then work on your memory sub-timings.

 

[Notime4games]

Thanks- I backed off slightly to 16-18-18-38 @ 3733mhz and then tightened up sub timings. All benchmarks higher than before, and no errors after a few hours of memtest. All good!

 

[EsaT]

Sub-timings can have big effect.
And if you left those at auto BIOS can relax those lot according to some general formula, leading to performance drop even if you tighten main timings.