Manual Overclocking AMD CPU

Disclaimer

There are multiple guides available for overclocking AMD CPUs. Many of them conclude that the built in automatic AMD overclocking solutions “Precision Boost Overdrive (PBO) 2” is superior to the old school manual overclock when it comes to a dynamic use of the CPU. However, there are other reasons for manual overclocking (OC) of the 5950X CPU, and one of those are the random reboot problem which has been discussed here.

I’ve had previous problems with a Ryzen CPU that rebooted randomly. I solved it by changing the “Power Supply Idle” option in the BIOS from “auto” to “typical”. My guess is that the motherboard, at times, gave the CPU too low of a voltage and it died.

My guess is that there is a similar voltage problem with the new CPU, and it seems that others have solved the issue by manually overclocking the CPU. By manually setting the CPU core voltage, the motherboard will constantly give the CPU the given voltage.

Resources

Parts

The CPU has a “max boost clock” of 4.9GHz. This is related to AMD’s “Precision Boost 2” technology available for Ryzen and Threadripper CPU series. Practically this is an automatic BIOS setting, that enables the CPU to dynamically run faster when needed. This can work as a guide line to how to start the manual overclocking. Further, the CPU has a “max operating temperature” of 90°C, which is good to take into consideration.

Introduction

Technically, we can overclock all components that use a clock to synchronize operations. Most commonly overclocked are CPUs, GPUs, and RAM.

When overclocking a CPU you increase its clock rate, which is the frequency the CPU operates on (clock cycles per seconds) measured in gigahertz (GHz), along with increasing the operating voltage. The CPU clock rate is not directly comparable between processors and brands, and there are many other factors in play such as memory latency and cache architecture, see the megahertz myth. Benchmarking is often used to evaluate the performance of different computer systems as it’s hard to directly compare their specifications.

Additionally to overclocking the CPU, the system memory (RAM) is usually overclocked as well.

The trade-offs for overclocking the CPU and the RAM is increased heat, fan noise, and shortening of components lifespan. Further, each CPU has a maximum stable clock rate, and beyond it the CPU cannot operate fully reliable. This can lead to issues such as silent data corruption. Sometimes it’s possible to increase the voltage such that the CPU can operate correctly at faster speed, and thus push the maximum stable clock rate. However, at some point the trade-off between all components are maxed out, and there is no way to get further stable performance from the CPU.

Requirements

Requirements for overclocking your CPU are a compatible motherboard and a good CPU cooler. Not all motherboards are equipped with BIOS software that allows for overclocking. Normally, the standard trade-off for higher performance is increased heat and power demands, therefore it’s important to have a good CPU cooler. Usually, a stock cooler is not good enough, and either water cooling or a larger air cooler is fine.

AMD recommends the following for overclocking:

Additionally AMD recommends the latest Windows OS as well as the latest drivers to the motherboard chipset, but this does not directly apply to Linux users.

Benchmarking

Benchmarking is used when overclocking in a few different ways. First, it’s useful for evaluating the CPU performance before and after overclocking. Second, it’s useful for finding your suitable overclocking configuration. One common method for overclocking is to start with the default BIOS settings, and gradually increase the clock rate. Here the benchmarking software can guide you since you do not want instability, and there can also be trade-offs between single core processing and multi core processing.

Two common benchmarking software for Linux are:

Stress testing

Stress testing is the practice of testing a system to its maximum usage. This is done to ensure stability of the system in the future. Stress testing software is similar to benchmarking software, but the difference lie in that the stress testing software pushes the system towards failure. Usually, stress test software, like Prime95, is run for 12-24 hours in order to ensure general stability.