Adjust the clock speed on Ryzen processors
Adjust the clock speed on Ryzen processors
Determining the optimal fclock speed depends on your system and workload. Since you're using a high-end R5 with 3200 MHz RAM, pushing it higher can improve performance. You've found that 1900 MHz feels smoother and more stable, while 1600 MHz gives you a higher base speed. The strange behavior you experienced might be due to increased load or other factors rather than the clock speed itself. Given your experience, sticking with 1900 MHz seems reasonable unless you notice further instability or performance drops.
The idea of what is “stable” varies from person to person. That’s not how I see it.
These CPUs generally struggle to maintain FCLK above 1900MHz. A few models can handle higher speeds, especially the single-core variants like the 5800X and 5600X, though such speeds remain rare. Most users encounter negative scaling beyond that threshold due to ECC support requiring careful tuning. In Y-Cruncher 1B, a 5900X running at 3800MHz with optimized BIOS dies in about 26 seconds. At slightly relaxed timings (3866MHz or 1933MHz), the same test can take over five minutes. Ensure your RAM and FCLK operate in sync to avoid significant delays. For certain tasks, extra multicore performance may help, but for others it can actually reduce efficiency. If your RAM only supports 3600MHz, running at 1800FCLK could offer a balanced compromise. If you have a capable RAM option supporting 3800MHz, go with that.
It seems there was a slight improvement in performance in some scenarios with earlier Ryzen models, though it wasn't substantial. The main factor is stability—consider running benchmarks and testing. You might also benefit from overclocking the RAM. I have 3200 MHz RAM (G-Skill FlairX 4x8GB CL14) operating at 3600 CL16, and it's performing consistently.
The SOP I grasp is to avoid doing nothing and instead begin at the next fastest speed to see if any timings fit. Memory pacing is well-known for being a difficult task. We don’t know if your specific memory will support 3400 cycles. It could work, it might not. Usually aiming for the highest possible number seems to ensure failure. We’re not sure what memory you have, and even if the PC model suggests a range, it doesn’t confirm whether that speed will actually be achievable. One part of the challenge is that heat sinks are often used by makers to mask the true condition of the parts.
Consider testing 3600 flat 14s at 1.45v, 3800 and flat 15s, which might be simpler with a bit more voltage, around 1.475-1.5v. Experiment to discover their capabilities.
Adjust the settings for a bit more flexibility and aim for around 3800mhz. The latest 3200c14 model reached close to 3733 at 1.5v, so pushing to 3800mhz should be realistic. Using the FCLK feature could improve performance slightly over 3600mhz cl14, even with a marginally higher latency. Feel free to tweak the subtimings—they can significantly boost speed.
i had a ram that was 3600 cl16 with stock xmp. i just preferred the 3200 cl14 setup, so i kept that. it wasn't a samsung b die, so i'm unsure if i can go up to 3800 cl16 or 3600 cl14. i recall 3600 cl15 was possible for mine, and also 3200 cl13, but i don't remember the exact timings anymore. 3733 and 3800 worked, though i don't know the timing settings.
Still, most RAM kits aren't that extreme that you can't slightly increase the memory frequency. I’d aim for up to 3800MHz and check how closely you can tighten the timings while keeping stability, it should offer the top performance. As long as you don’t have to widen the timings too much to maintain stability, it should deliver the best results.