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.



The E-Core side of this chart (threads 13 to 20) can be somewhat misleading. It looks like the cores run at increasingly slower frequencies as the load goes up, but that's not the case. The frequency plotted is the average of all the P-Cores active, plus more and more E-Cores, which all run at a lower frequency than the P-Cores, which drags down the average.

That's why I tested E-Core frequency scaling separately in the chart below.



The E-Cores always run at 3.9 GHz, no matter how many of them are loaded.

Overclocking

Overclocking the Core i5-13600K is easy, thanks to its unlocked multiplier. While heat was the biggest problem on 13900K, this is not so much an issue on the 13600K, so you can give it more voltage for higher clocks. You'll still be running very high temperatures, so the approach is "find max voltage that you can cool, then find max multiplier"—same as on the 13900K. I settled for +0.135 V, which gave me a fully stable all-core OC of 5.6 GHz on the P-Cores, plus 4.4 GHz on the E-Cores.

While in some benchmarks performance is increased considerably, on average, the performance gains are minimal, at the cost of much higher temperatures and power consumption.