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Question CPU Benchmark Dropped 10-15% After OCing Memory

Notime4games

Junior Member
Aug 15, 2020
2
0
6
Hi, I followed DRAM Calculator (memory data imported 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. Is it abnormal that I was able to increase the frequency while tightening timings? All runs smoothly though, 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
 

damian101

Member
Aug 11, 2020
102
38
61
That's quite a big performance drop. Maybe PBO behavior somehow gets affected by the RAM overclock, have you looked at the core frequencies during benchmarking? I would also try the benchmark with Gear Down Mode enabled, maybe there's a reason why it's always enabled by default on Ryzen platforms.
 

DrMrLordX

Lifer
Apr 27, 2000
16,493
5,474
136
Only reason I can think it might be happening is that the I/O die may be eating into the package power budget. And that's a stretch.

Have you observed any reduction in benchmark scores in anything other than Passmark? How about CBR20?
 

Notime4games

Junior Member
Aug 15, 2020
2
0
6
I backed off slightly to 16-18-18-38 @ 3733mhz and then tightened up sub timings and enabled Gear Down Mode. All benchmarks higher than before, and no errors after a few hours of memtest. Haven’t tried CB20 but will.
 

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