ElI5: how is each CPU unique even tho they’re labelled the same? For example a Ryzen 9 5900X can be better than another Ryzen 9 5900X.
In: Technology
The issue with the ryzen 5000 series, is that the CPUs use an advanced “speed boost” technology, where the CPU selects the best possible speed, taking into account current conditions, as well as the manufacurting variations that happen when making a CPU.
There is natural variation when making chips – the manufacturing scale is so small, that there will always be some variation in the production process. Some chips, or circuits on a chip, might not work. Some chips (or individual circuits, like a CPU core) might be less energy effieicnt, and some might be more energy efficient. Some might run faster, some might only manage a slower speed.
Traditionally, CPU manufactures would test the chip under worst case conditions, and if it passed, then that would be the chip’s speed. If it didn’t it would be sold as a slower speed; if it couldn’t meet the slowest spec in the series, it would be scrap.
Manufacturers realised that worst case stress testing wasn’t always realistic, and under other types of work, there is less heat and power consumption, which means that the chip could be pushed a bit harder when running “easier” work, as long as it slowed down again when running “hard” work. This was a concept called “turbo” or “boost”. The early generations of boost technology worked on the basis of workload and temperature
The Ryzen 5000 series has a 2nd generation boost system, which will push the chip right to its limits at the current conditions, taking into account not just the program workload and temperature, but also the speed profile and energy efficiency of each individual core in the CPU (which is measured at the factory, and programmed into the chip), as well as the capability of the CPU’s power supply.
On the 5900X with 12 cores, if it is running maxed out on all 12 cores, the limiting factor is the power supply. The CPU slows down the cores as needed, taking into account the energy efficiency of each individual core, and the nature of the program, so that the total power consumption of the CPU, is close to the CPU’s maximum allowed power capability, without going over.
What this means is that if 1 specimen of a 5900X is more energy efficient, then it will be able to run faster, because the boost system will always adjust the all-core speed to be just at the limit of the power supply.
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