M5 vs Ryzen 9 9900X3D
A side-by-side readout for tdp.
Understanding tdp
TDP is a thermal design specification. Coolers and chassis are designed to dissipate the TDP figure indefinitely without throttling.
Why it's not power consumption
Modern CPUs and GPUs can briefly exceed TDP during boost (Intel's PL2, AMD's PPT, NVIDIA's power limit). They also dip below TDP at idle. The TDP figure is the sustained-load expectation, not a constant draw.
Why it matters
- Laptops. Lower-TDP chips fit in thinner chassis with longer battery; higher-TDP chips need beefier cooling.
- Mini PCs. A 65 W chip in a 0.8 L chassis will throttle. A 35 W chip will not.
- Desktops. Drives PSU sizing and case fan choice.
In comparisons
Two CPUs with the same TDP and similar specs will usually feel similar in real-world use. Big TDP gaps (35 W vs 125 W) reliably predict large performance gaps under sustained load.
This matchupRyzen 9 9900X3D's 120W is roughly 445% more than M5's 22W (a 98W gap). Lower is better here, so M5 takes the lead in real use.
What is tdp?
Thermal Design Power — the maximum sustained heat output a CPU or GPU is designed to dissipate, measured in watts. A guide for cooler sizing, not an absolute power consumption number.
Read the full TDP explainer →Other specs on this comparison
See the full CPUs category for all products ranked by Mars Score.