One of the biggest concerns of enthusiasts when choosing a graphics card is not only the performance of the GPU itself, but also the clock speed it can achieve, especially in Boost mode, because this results in better performance.
What is GPU Boost?
The concept of GPU Boost is analogous to the same concept in processors, so we are talking about situations where the GPU increases its clock speed in order to render what we see on the screen faster. This results in an increase in frame rate and / or image quality.
Before the advent of Boost mode, which was first seen on GeForce 600s based on their Kepler architecture, the clock speed at which a GPU was running was always the same. This was regardless of external elements such as power consumption and graphics card cooling.
Boost mode is therefore the maximum to which a graphics card can go. Imagine a runner who begins to go faster to pass, but suddenly becomes exhausted on exertion and begins to run at a constant speed. It’s the analogy with GPU Boost mode.
How does Boost mode work on a GPU?
The operation of Boost mode in a GPU is very simple, today GPUs have a large number of sensors inside that measure the health of the graphics card. These sensors measure the temperature of the various components, the voltage at which they are operating and the clock speed. This allows them to give full information to the CPU about the status of the graphics card at any time.
When the temperature and consumption leave room for improvement, it is when the Boost mode can be activated. Which is implemented as a second clock signal on the pins that connect the GPU to the graphics PCB. When Boost mode is activated, the standard speed clock signal stops and the Boost signal activates. When the GPU approaches the temperatures and power consumption essential to its operation, it is when it returns to standard clock speed.
This is why the cooling systems of a GPU are very important, because they allow the boost mode to be maintained for a longer time. In addition, if the GPU architecture allows it, it is possible to configure clock speeds higher than those indicated by the manufacturer, although in many cases these clock speeds are only durable under cooling conditions. more advanced such as the use of radiators for liquid cooling. .
GPU boost mode and voltage management
In the power consumption of any processor, voltage is directly related to the clock speed it can achieve. The relation is that the higher the clock speed, the more the voltage increases and with it the consumption, but there are clock speeds which are reached with several different voltage levels.
For example, it is possible for a graphics card to reach its clock speed in Boost mode with a voltage of 1.2 V, but it can also reach it with a voltage of 1.05 V, decreasing the voltage at which the GPU is operating results in a decrease in the power consumed and therefore a longer time during which the GPU can operate at this speed.
The tradeoff is that the design of the GPU may not allow its clock speed in Boost at the lowest voltage. The idea is not to achieve the highest Boost speed, as it does not make sense to have peaks and valleys in clock speed. What one seeks by lowering the voltage is to be able to reach a higher stable clock speed in a longer period of time. Which by definition goes against the Boost concept which is based on small speed boosts.
The other game is overvoltage, where the input voltage becomes higher. Keep in mind that there are graphics cards that require the use of higher voltage to achieve higher clock speeds. Which means an increase in consumption by increasing the clock speed higher and a much shorter Boost time. It is unusual for a GPU to have to increase the voltage to achieve Boost speed.
Is this possible in the integrated graphics?
In an SoC, the Boost mode of a GPU works differently, since the GPU is not alone and is usually accompanied by a CPU. The reality is that the temperature and power consumption of one will eventually affect the other in a zero-sum game where neither party will be able to hit maximum clock speed without limiting that of the other.
Does this make GPU Boost impossible on an SoC? No, that doesn’t make it impossible and we have an example in the recently launched PlayStation 5 console that can speed up its GPU clock speed beyond 2.2 GHz, a very high speed for an SoC. What you can do is that one unit measures the power consumption and heat of the SoC at all times.
One way to measure the power consumption of a processor, be it CPU or GPU, which is starting to appear is to measure the consumption not only by voltage and temperature sensors. But since not all instructions consume the same power, the power consumption of each one starts to be taken into account so that the speed fluctuates not only by periods but by instructions or groups of instructions.