Clock Frequency and Boost Analysis

Let's cut straight to the chase with boost. The controversy surrounding boost with 3rd generation Ryzen processors focuses on a large number of users observing that their processors seldom or never reach their maximum advertised boost frequency, which is generally reserved for single-threaded workloads on both AMD and Intel. The advertised maximum boost frequency for the Ryzen 9 3900X is 4.60 GHz. With the older BIOS, the chip indeed fell short of the 4.60 GHz-mark in single-threaded workloads.


With the new BIOS that has AGESA 1.0.0.3ABBA, we see that AMD's claims do check out. Our 3900X processor not only reaches 4.60 GHz, but exceeds it by up to 110 MHz, reaching 4.71 GHz with the average ending up at 4.65 GHz. With up to 2 threads (1 core), the chip keeps up with this frequency. As we step up to 3T and 4T (2 cores), clock speed drops to 4.575 GHz, which is still 50-75 MHz higher than on the older BIOS.

As we move up to 5T, there is a sharp drop in boost frequency down to 4.40 GHz, which holds until 12T. Throughout this plateau, the new BIOS runs the chip roughly 20 MHz higher than the older BIOS. The next sharp drop happens at 13T, where the chip drops to 4.30 GHz, while still staying 50 MHz faster than on the older BIOS. From here onward, there is a gradual reduction in clock speed with increase in core counts until it settles down at 4.20 GHz all-core. Throughout, the new BIOS runs the chip at marginally higher frequencies. In theory, these slightly elevated boost frequencies should result in minor performance increases, particularly in less parallelized workloads. We put this to the test in the following pages.