Clock Frequencies

The following chart shows how well the processor sustains its clock frequency and which boost clock speeds are achieved at various thread counts. This test uses a custom-coded application that mimics real-life performance—it is not a stress test like Prime95. Modern processors change their clocking behavior depending on the type of load, which is why we provide three plots with classic floating point math, SSE SIMD code, and modern AVX vector instructions. Each of the three test runs calculates the same result using the same algorithm, just with a different CPU instruction set.

Overclocking

Overclocking the Ryzen 7 9950X is pretty easy, thanks to the unlocked multiplier.

For manual all-core overclocking I dialed the voltage up to 1.30 V, which is about the maximum I could run heavy loads at without overheating. I then dialed the clocks up until the system was unstable. While I could boot and run many lighter workloads, including games at 5.3 GHz, heavy loads kept crashing the system. Ultimately I settled for 5.2 GHz all core, which is an "ok" overclock, considering the stock max boost rating of 5.7 GHz. As our performance results show, in light loads, the "PBO Max" config will achieve better performance, because it can reach clocks higher than 5.2 GHz. In other workloads such as rendering, the 5.2 GHz all-core OC ends up with higher clocks, because PBO is more cautious in that setting.

Overclocking using PBO/Curve Optimizer works exactly the same as before. There's a new feature called Curve Shaper, which lets you adjust the Curve Optimizer voltage dynamically based on frequency and temperature. We will have a longer article on this in the future. At this time changing Curve Shaper values is done manually by entering numbers. BIOS vendors are working on implementing GUI-based controls for this, AMD will also add an easy-to-use interface to Ryzen Master.

• Maximum FCLK is between 2100 and 2200 MHz, so no significant changes from Zen 4.
• Same with memory, which tops out around 6400 MHz unless you're engaging a 2:1 divider, which will likely have mixed performance results.
• The thermal target/limit is still 95°C, and can't be raised, same as before. When manual overclocking (= all-core multiplier) is enabled, the temperature limit is 115°C, same as before.