Things you forget to check about CPU in performance testing

Majority of time performance engineers overlook the fact CPU and CPU clock frequency used in the servers. I have seen many of performance engineers report different results when they test in test environments and newly built Pre - Prod environments. Sometimes, production environments show better or improved response times compared to what performance engineers reported in their report of performance test which they conducted in test environment even when the number of CPUs are same. There are many factors related to CPU that impact performance but in this blog I wanted to highlight few things which many performance engineers forget to check before conducting the performance tests.

The CPU is the brain of the server, and the performance of the CPU impacts the performance of the webpage. In this blog, we will discuss how performance engineers often forget to ask about the CPU used in servers and how CPUs from different brands and their frequency impact the performance of a webpage.

CPUs main job is to execute instructions faster and do all the calculations with minimal effort. The performance of the CPU depends on the clock speed, the number of cores, cache size, and the architecture of the CPU. The higher the clock speed and the number of cores, the better the performance of the CPU.

Performance engineers need to ask about the CPU used in the servers and the brand of the CPU. CPUs from different brands have different architectures, clock speeds, and cache sizes, which can impact the performance of the webpage. Intel and AMD are the two most popular brands of CPUs used in servers. Intel CPUs are known for their high clock speeds, while AMD CPUs are known for their high core count.

The frequency of the CPU is also an important factor that impacts the performance of the webpage. The clock speed of the CPU determines the number of instructions it can execute per second. A higher clock speed means more instructions can be executed in the same amount of time, leading to better performance.

In addition to the clock speed, the cache size of the CPU also plays a crucial role in the performance of the webpage. The cache is a small amount of memory located on the CPU that stores frequently accessed data. A larger cache size means more data can be stored, resulting in faster access times.

?Even if your application is based on docker containers, do check these information from physical host. In fact, in shared environment like dockerized world, CPU cores matter the most.

?In conclusion, next time when you prepare performance plan document which includes details of hardware used in performance testing or next time when you plan to test your performance test suite against different environment make sure to check model type (intel or AMD), number of cores, clock speed, cache size of the host server.

?Linux command to check all these information on linux host: lscpu