You often see TDP measurements on spec sheets and that’s important information for people with desktop PCs. But TDP definitions are like opinions — everyone has one. Let’s clear up the confusion and talk about what the TDP number means to you.
What does TDP mean?
TDP is an acronym used by people to refer to all of the following: Design Thermal Power, Design Thermal Point, and Design Thermal Performance. Luckily, they all mean the same thing. The most common is Thermal Design Power, so we’ll be using it here.
Thermal design power is a measurement of the maximum amount of heat generated by a CPU or GPU under heavy workload.
Components generate heat when a computer is running, and the harder it runs, the hotter it gets. The same goes for your phone. Play a game like » Brawl Stars, about 30 minutes and you will notice that the back of your phone gets warmer as the components use more power.
Some PC enthusiasts also refer to TDP as the maximum power a component can use. And some companies, like NVIDIA, say it’s both:
«TDP is the maximum power a subsystem can draw for a ‘real world’ application, as well as the maximum amount of heat generated by a component that a cooling system can dissipate in real-world conditions.»
However, in most cases, TDP refers to the amount of heat that a component generates, and the cooling system must remove it. It is expressed in watts, which is usually a measure of power (such as electricity) but can also refer to heat.
TDP is often used as a substitute for power consumption because both are often equivalent or close. However, this is not always the case, so you should not use TDP to determine the size of your PC’s power supply.
TDP for processors
AMD vs. Intel
If TDP is based on the amount of heat generated during a heavy workload, who decides what that workload is or what clock speed the chip should run at? Since there is no standardized method for estimating TDP, chip manufacturers have come up with their own methods. This means that PC enthusiasts have very different opinions on TDP for Advanced Micro Devices (AMD) compared to Intel processors.
In general, enthusiasts claim that AMD’s TDP numbers are more realistic. Meanwhile, Intel often publishes TDP ratings that are lower than those of people running their systems, making TDP less reliable as a substitute for power consumption.
Anandtech recently explained how Intel achieves its TDP ratings, and why they always seem to be off. Processors run at their boost levels (higher speeds) when under load for extended periods of time. The problem is that Intel bases its TDP ratings when the processor is running at base frequency, not boost. So the Intel processor is often faster than what Intel says you can expect on the box. If the system cooler can’t handle these higher heat levels, the CPU slows down to protect itself from damage. This leads to a decrease in system performance. However, when using a better cooler, these problems occur less often.
Meanwhile, on the AMD side, there are a lot of forum posts where people claim that even with moderate overclocking, stock AMD coolers are more than enough.
It’s all about cooling
You can manage your system’s TDP if you use the best CPU cooling solution. If you’re not doing any special tweaks to your system or long running AAA games, the stock cooler that came with your CPU should be fine. Gamers, however, should look around, especially if you’re playing games that rely heavily on the CPU.
An aftermarket cooler can most likely handle whatever heat your CPU throws at it. This webpage lists over 60 coolers from Cooler Master, a renowned PC hardware manufacturer. More than half of them have a TDP rating of 150W or higher, which should be enough for most consumer-grade processors. You can find CPU coolers in all price ranges. There are liquid-cooled solutions that cost hundreds of dollars, as well as 150-watt heatsinks and fan coolers that cost between $20 and $50.
The right cooler is only part of your PC’s heat dissipation system. Proper airflow is also key. Be sure to check out our article on how to manage your PC’s fans for optimal airflow and cooling.
TDP, T-Junction and Max Temps
TDP will help you choose the right type of cooling system for your processor. However, it does not say how much heat the component can withstand. To do this, you need to look at one of two things.
If you have an Intel processor, you need to check the T-junction. Intel says this is «the maximum temperature allowed on a processor die». «Matrix» refers to tiny areas of circuitry on a silicon wafer. For example, for the Core i9-9900K, the TDP is 95W and the T-junction is 100 degrees Celsius. To find the T-connection for your processor, go to the Intel Ark site and find your processor model.
At the same time, AMD uses the simpler term «Max Temps». The Ryzen 5 3600 has a TDP of 65W, the Ryzen 5 3600X has a TDP of 95W, and both top out at 95 degrees Celsius.
These are good numbers to know if you need to troubleshoot a computer that is overheating. In general, however, it’s best to focus on TDP first.
For mainstream consumers, TDP is more important for processors. Graphics cards have TDP, but they also include built-in cooling solutions. You can purchase GPU coolers, but these are harder to install and generally not needed unless you’re heavily overclocked. If you want to know the TDP of your graphics card, TechPowerUP is your trusted source.
Thermal design power is an important specification, especially for processors. But don’t get confused by its meaning. TDP will help you choose the right cooling solution for your components. That’s all.