Comparing processors may seem easy. If you have a model with higher GHz frequency, it should be better. However, this is a myth. The GHz frequency is not entirely responsible for your processor performance. In order to understand the myth of GHz for computer processors you can read this article.
The simplification of a CPU GHz frequency determining performance is more a marketing strategy than reality. Two processors with different GHz frequencies may perform in opposing ways to the technical file. In fact, a CPU with less GHz may perform better when playing videogames, running demanding software or tasks.
Understanding the myth of GHz frequency
The frequency of your CPU measures how many cicles can your processor execute per second. It doesn’t relate to the useful work or completed tasks in each cycle. When talking about performance, a CPU includes diverse factors- It’s not only about frequency, but also architecture, IPC, cache, latency, bandwidth, number of cores and turbo time. Although GHz is still important, it’s not the only feature to determine how a processor runs.
Intel itself explains that clock speed is the indicator of processor cycles per second. In theory, a higher frequency allows for lighter loads and better performance. But in fact, it’s incomplete information. It can’t reflect how many useful instructions the core runs in a cycle. If you want to compare different architectures and core performance, you can use the IPC or Instruction Per Cycle number.
A practical example, your current GPU can run at 3,8 GHz and perform better than a 4,5 GHz processor if the design is more efficient. When your CPU has improved execution units and a more powerful front-end, the frequency is not that important.
IPC and the average useful work are more related to the real performance of a processor. Bottlenecks usually appear when cache, backend or access memory fail but are not entirely related to the GHz frequency.
Turbo, heat, cores and cache factors
A CPU is not only important because of its clock. The cache has a powerful impact as it reduces the waiting time for data receiving. Processing analysis shows that cache fail and memory latency affect performance much more than GHz frequency. That’s why a better design in cache as in the latest AMD models performs better even with less frequency.
Cores and threads are also relevant when talking about CPU performance. In high performance tasks like video editing, renderization or compilation, a CPU with more cores is better than the myth of GHz number. Turbo time is also important because there are processors than only reach certain speeds under very specific conditions. If the chip overheats, the speed goes down in order to protect the components. So the GHz in the box is not that important.
Basically, the GHz are important but they work in a certain context depending on each device. If you want to know if your CPU is faster, you need to look the architecture, IPC, cache, cores and real benchmark tests.