Knowing how many watts a graphics card consumes is not a very difficult task for any of us to carry out. Currently we have applications that are able to measure quite accurately what power is consuming not only our dedicated graphics card, but also the integrated graphics, CPU, and even SSD.
Index of contents
- TGP vs TBP vs TDP What do we measure?
- How many watts consumes a real graphics card
- Wattmeter (full pc)
- Nvidia PCAT Tool
- Measure watts consumes a graphics card using software
- Measuring consumption with GPU-Z in a laptop
- Measuring consumption with HWiNFO on a laptop
- Measuring consumption by software on a desktop card
- Comparison between PCAT and GPU-Z in consumption measurements
- Conclusions about the consumption of graphics cards
Thanks to the fact that there are sensors placed in almost any corner of our components, we can get an idea of the easily consumption of a desktop or laptop PC . If we go a little further, we will also find simple and cheap tools such as wattmeters that will measure the complete consumption of our equipment, multimeters or exclusive tools such as the Nvidia PCAT specially designed to measure the consumption of complete GPUs, thus discovering its TGP.
TGP vs TBP vs TDP What do we measure?
Well, it will be the first thing that must be made clear, the concepts that involve the consumption of a hardware component such as the graphics card. And there is a lot of confusion between what is a TDP and a TGP , as they are two very repeated measurements by manufacturers and reviewers.
The TDP or Thermal Design Power defines the power in watts that a component can draw for a real world application. In other words, more understandable, it will be the maximum amount of heat that a component will generate at maximum performance , and that the cooling solution must be able to evacuate. We are not talking at any time about consumption or power, only about the heat it generates, and it can be not only a GPU but also a CPU or another chip.
To talk about real consumption we have to refer to TGP or Total Graphics Power . This determines the power that must be supplied to a graphics card to function in a maximum stress application. The TBP (Total Board Power) will be practically the same and the difference is that Nvidia uses TGP and AMD uses TBP . This is what we intend to measure in this article.
How many watts consumes a real graphics card
When we refer to real, it means the watts that we can physically measure with a device external to the graphics card, which is not processed by a software and system that distorts the measurement to a greater or lesser extent.
We could currently do this in three different ways, always with external tools and requiring a small outlay of money, although in a certain way limited in some respects.
Wattmeter (full pc)
The wattmeter will be a device capable of measuring the power consumed by a device connected to it. So we must place it between the plug and the device , being able to measure the watts consumed in real time .
Depending on the quality and price, they will have more or less integrated functions, for example measurement of intensity, voltage, even estimated consumption. For just 15 euros we can have a good wattmeter for our equipment.
Their limitation is that they will only measure the total consumption, not of each component separately, so they will be useful to calculate the total consumption by adding the different devices , or the power that comes out through a plug.
The multimeter is another device that can measure different electrical quantities among which we have intensity, voltage, resistivity and sometimes also power. Because it has two probes that we can place wherever we want , we will have some freedom. Of course, we need to be clear about some notions of electricity , at least to know how to calculate magnitudes from others.
But this also has a disadvantage, and that is that we will not be able to measure several things at the same time , for example the power delivered by the card’s PCIe interface and by the power connections. For this we should do it one by one and knowing exactly where to put the probes . Another problem that appears is that, in case of not being able to measure the power directly, we would have to calculate it manually with the formula P = I x V ;Power = Intensity x Voltage .
The multimeter will be a very useful tool to check possible component failures, continuity in electrical tracks and circuits.
Nvidia PCAT Tool
Finally we have a tool that is specifically designed to know how many watts a graphics card consumes . It is made up of two elements: a PCIe x16 adapter that will measure the consumption of the graphics card directly through its interface . And a small board that records the power that passes from the power supply to the card headers.
In this way it is possible to accurately measure the total consumption of the card . The information can be seen directly on a small OLED screen connected to the PCB, or from the operating system as it can be connected via USB and controlled by software . This tool will work for both Nvidia and AMD dedicated cards, but not for built-in GPUs or laptops, but for the mentioned ones, it is the most reliable and accurate way to measure it .
But there is also a problem with this tool, and that is that it is not for sale , at least for now, and it is only possible to obtain it by approval of the brand, for technicians and means of analysis.
Measure watts consumes a graphics card using software
We don’t have time for lows, because now is the time for the good news. And we can also measure the consumption of a graphics card through monitoring programs available for Windows. They will also be free, have a lot of precision and are capable of measuring many more aspects.
The two applications that we will test will be on the one hand GPU-Z focused specifically on graphics cards, and on the other HWiNFO , which provides information on all the hardware of our equipment.
Measuring consumption with GPU-Z in a laptop
To give us an idea of how complete this simple tool can be, we are going to measure all the consumption data that we can from a laptop with an integrated and dedicated GPU . Something that will be extendable to desktop computers, although we believe that this example will be more complete. The laptop will be a Razer Blade 14 with Nvidia RTX 3080 dGPU and with AMD Radeon Graphics iGPU.
Watts consumed by dedicated GPU
The first thing we should know is that Nvidia indicates in its specifications the TGP of its Ampere graphics cards, the most current, something that it did not do in previous generations. So this measure should coincide with the actual consumption of it.
We can know this TGP by opening the Nvidia control panel located in the right area of the taskbar, and opening the System Information window . In this new window, the line Maximum graphic power will appear , showing the maximum consumption that the laptop’s GPU should have.
In the case of desktop graphics cards, the TGP will not appear in the Nvidia control panel. Although the brand says so in its specs
Next we open GPU-Z , and on the lower edge we select the Nvidia graphics card, which we will obviously identify by its name and specifications. We will go to the Sensors section , where we will find a large amount of telemetry data for the card. Board Power Draw will be the line that tells us the total consumption of the graphics card.
If we use a stress program like FurMark to put the GPU to the maximum, we will discover that indeed, the consumption is almost completely adjusted to those 100W of TGP . If we also display the date on each line, we can select what information is displayed, such as real-time, average, minimum or maximum data.
Watts consumed by the integrated GPU
We will do the same procedure with the integrated graphics of the Ryzen 5900HX , which equips 8 Radeon Graphics cores without specifying its TBP. We proceed again to stress this GPU to see that the consumption will be from 34 to 52W , with quite a few peaks unlike the dedicated GPU.
With AMD’s integrated graphics, we can also use Radeon Software’s own driver software to monitor consumption . We will see that the data will match, so it is an extra step that we can also take.
Measuring consumption with HWiNFO on a laptop
We can do practically the same with the HWiNFO software , although it will give us much more telemetry data from other elements of the PC such as CPU, SSD, board sensors, etc.
We will start the software in Sensors Only mode , appearing a dense table divided into sections for each element. We will focus on the two GPU sections that show data from the two chips equipped in the laptop.
Doing the same stress procedure, we will verify that the consumption coincides with GPU-Z bordering on 100W , same voltages, frequency and others. We will do the same for the RTX 3080 Laptop and the Radeon Graphics, showing similar results.
It is therefore shown that both applications are going to be just as good at knowing how many watts a graphics card consumes at least in a laptop.
Measuring consumption by software on a desktop card
We will do the exact same thing on a desktop PC equipped with an Nvidia RTX 3080 , using HWiNFO and GPU-Z simultaneously , performing a stress with FurMark. This graphics card specifies a 320W TGP, and seeing that it matches laptop GPUs, the same should happen here.
In this case, the differences between the two measurements are barely 2W, and we also see that it practically coincides with what the manufacturer is actually specifying for this card.
Thanks to this reliability in the measurements , we can also discover if a custom assembled model is adjusted with this same TGP or has been given a squeeze to improve its performance. Bear in mind that these normally use watches that are augmented with respect to the reference model in order to obtain more performance, and consequently, the manufacturer could have increased its TGP. This will happen on both Nvidia and AMD cards.
Comparison between PCAT and GPU-Z in consumption measurements
One last check we can do is to compare the consumption measure that the PCAT tool gives us, which should be more real, and that of GPU-Z or HWiNFO. In this way we can definitely know if they are equivalent and consistent.
And the conclusion we can draw is that yes, they will be very similar tools looking at the delivered measurements . We see that the PCAT measures a little more than those 320W that the GPU offers, while the GPU-Z falls a little under with 313W in the snapshot. In others, this figure rises to almost constant 318W, so the difference is less than 10W, enough to affirm that the programs are very reliable.
Conclusions about the consumption of graphics cards
Knowing how many watts a graphics card consumes is quite important when choosing a suitable power supply. for our setup. We see that the applications used are as reliable as specific tools and not very accessible as PCAT, so they are perfect for this task.
Not only for GPUs, as we can also know the maximum consumption of the CPU or storage units in order to have even clearer the choice of components and cooling. In the case of laptops, we will also see if the consumption is adjusted to what is specified and if the heat is reducing the performance due to throttling.
On the other hand, the wattmeter or multimeter style tools are less attractive due to the little versatility they allow , and the need to invest a sum of money in their purchase. We finish this article and hope that it has been useful for all of us to learn how to measure and interpret the telemetry data of our hardware.