Is the CPU infinite

Therefore, the CPU clock rates are currently no longer increasing

Friedrich Stiemer

Currently, even with expensive high-end processors, there hardly seems to be any increase in clock rates. That is the background.

EnlargeTherefore, the CPU clock rates are currently no longer increasing

Until recently, processor clock speeds continued to increase year after year. An example: In the 90s and in the early 2000s there were drastic increases in speed from 60 MHz to gigahertz clock frequencies. In contrast, even with expensive high-end processors, there seems to be hardly any increase in clock rates in recent years. Experienced overclockers can currently overclock some CPUs up to nine gigahertz. However, this only works with the help of cooling systems that use liquid nitrogen. This is not a common practice in everyday PC life. This ends at around five gigahertz.

And companies are not making any big leaps either: a few years ago, Intel planned the market launch of a processor with a full ten gigahertz, for which we are still waiting in vain today. It cannot be assumed that anything will change in this regard in the near future. The question arises why the increase in clock frequencies is actually stagnating. Have the limits already been reached, or will the Hertz numbers soon go up?

To the background: Moore's law, known in IT, states that the size of the transistors shrinks at regular intervals. This means that more transistors can be integrated on a processor, which is usually associated with an increase in performance. But there is also another factor that influences this - Dennard scaling. This principle states that the energy required to operate transistors within a certain volume unit remains the same even with an increasing number of transistors. However, we are already reaching the limits of Dennard scaling. Therefore, leading experts worry that Moore's law will slow down. In the meantime, transistors have become so small that Dennard scaling is no longer effective - on the contrary: the transistors are shrinking, but the energy required for operation increases.

EnlargeA few years ago there were huge increases in CPU clock frequencies. However, they are currently stagnating. This is due to various factors.

Thermal conditions also play an important role in chip design. Because if you integrate billions of transistors on a common chip surface and switch them on and off thousands of times per second, then a lot of heat is generated. And excessive heat isn't exactly the best friend of the silicon used in the chips. This heat must therefore be dissipated in order to maintain the clock frequencies. In other words: the more transistors are integrated, the more efficient the cooling system has to be.

An increase in the clock rate also requires an increase in voltage. This leads to a higher power consumption of the chips. So if the clock frequencies are to increase, heat and power consumption increase in parallel. In fact, both factors have more influence than the actual cycle and are therefore the main reasons for the current standstill.

The design and composition of the transistors themselves also prevent the clock rate from increasing any further. They are getting smaller and smaller, but they are not working any faster. Before that, transistors got faster and faster because their so-called gates (the part that moves in response to the current) became thinner. But since Intel's 45-nanometer process, the transistor gates are around 0.9 nanometers thick and thus roughly as wide as a single silicon atom. Although other materials for the transistors could enable faster gate operation, the lush increases in speed like a decade ago are no longer to be expected even with this.

Furthermore, the speed of the transistors is no longer the only decisive factor for the level of the clock frequency. Nowadays, the lines that connect the transistors together are also an important factor. And not surprisingly, if the transistors shrink, then these lines also shrink. But the smaller these connections get, the greater the impedance and the lower the current. The "Smart Routing" technology can help to reduce the transmission time and heat generation, but dramatic increases in clock rates are physically impossible in this case.

All of these reasons ensure that there are no faster processors so far. In fact, due to the physical limitations and the current transistor designs, no increase in clock rates is possible at this point in time. Instead, the computing power is to be increased with the help of multicore processors, as AMD has been doing since the Ryzen generation. Because despite the not too high clock rate, these are extremely powerful CPUs, as they have eight or more computing cores. Software and games are not yet optimized for this, but that will probably change soon.

Tip: CPU tuning: When the load is almost 100 percent ...