- Nov 2, 2018
- Only one core on our Ryzen 5 3600X processor will hit AMD's rated boost frequency. AMD confirmed some cores in Ryzen 3000-series processors are faster than others, which is denoted in Ryzen Master. That means that not all cores on can hit the single-core turbo frequencies. Instead, there are a mix of fast and slow cores.
- We recorded up to a ~75 - 100MHz difference between the fastest and slowest cores, with only one core reaching the single-core boost frequency. AMD hasn't shared the definition of the frequency that is acceptable for slower cores (it is rational to expect this to be the base frequency). While we recorded relatively small frequency deltas in our sample, it impacts performance and denotes a shift in AMD's binning strategy compared to the per-core turbo performance of Zen/Zen+.
- Previous-gen Ryzen processors can reach boost frequencies on all cores. Intel also says its processors can reach the turbo frequency on all cores.
- Workloads running on Ryzen 3000's slower cores experience lower frequencies than the chip's rated boost speed, and thus lower performance.
- The combination of Windows 10's new Ryzen-aware scheduler and AMD's chipset drivers allow the operating system to schedule single-threaded tasks into the fastest cores (thread pinning). AMD has previously disclosed the Windows 10 scheduler and the CPCC2 feature, but not that the combined features assign threads to the fastest cores. This functionality requires the latest version of Windows 10. This is somewhat similar to Intel's Turbo Boost Max 3.0 on its HEDT processors, but Intel doesn't set this as a requirement to reach the normal Turbo Boost 2.0 clock speeds.
- Older versions of Windows cannot schedule threads into the fastest cores as efficiently, thus resulting in lower clock frequencies and performance for Ryzen 3000-series processors in some workloads, which may be at the root of many user complaints.
- Most test utilities do not measure performance fast enough to catch bursty frequency boost activity. They also do not measure certain types of power states that could indicate higher boost activity.
- We theorize the slower cores could be a contributing factor to low overclock ceilings with Ryzen 3000 processors. Ryzen 3000 series processors hit all-core overclocks 200-300MHz below the single-core boost frequency. Slower cores simply may not be able to achieve/sustain higher frequencies, thus serving as the weakest link in the chain.