Vivo X100 Pro crumbles under stress as Dimensity 9300 reportedly thermal throttles to less than half of max performance

Update (November 29)

Concerning our report about the purported thermal throttling of the Dimensity 9300, MediaTek reached out to us with the following response:"

1. It is well known that all modern smartphones include thermal throttling to ensure the device temperature stays in an acceptable/safe range.
2. A better way to use the CPU Throttle Test as a way to compare devices side by side, would be run the test with same device case temperature.
3. With MediaTek’s big core CPU architecture, the Dimensity 9300 will achieve a much higher max & average score than the competitors if the testing is done correctly. In summary, the Dimensity 9300 will be able to deliver more computing performance across the span of the test."

The original story continues down below.

We recently reported that although the Cortex-X4 core inside the Snapdragon 8 Gen 3 affords a lot of raw CPU performance, the core was found to consume a whopping 28% more energy than the Cortex-X3. Since MediaTek decided to only pack eight performance cores including four Cortex-X4 cores and not use any efficiency-focused smaller cores in the flagship Dimensity 9300 SoC, speculation was high that the chip could potentially thermal throttle owing to increased power consumption. This seems to be the case, as a new Dimensity 9300 benchmark shows the SoC throttles rather aggressively when pushed.

The CPU Throttling Test was conducted by Sahil Karoul on the Vivo X100 Pro, Vivo’s flagship smartphone that debuted earlier this month with a promising Zeiss camera setup that seemingly produces better macro shots than the Galaxy S23 Ultra (Available on Amazon).

Sahil’s test shows that the Dimensity 9300 throttles to a disappointing 46% of the max performance after two minutes of the benchmark run. This throttling behavior sees the core clocks take a massive hit as one of the cores drops to only 0.6 GHz vs the max CPU frequency of 3.25 GHz. Considering the fact that the Vivo X100 Pro packs a vapor chamber cooling solution, the Dimensity 9300’s performance drop due to the thermal throttling becomes even more concerning.

It seems Sahil Karoul is not the only one who has noticed the performance degradation of the Vivo X100 Pro under stress. C4ETech noticed in their Vivo X100 Pro review that, although the Dimensity 9300 is pretty powerful, the phone got a disappointing stability rating of only 40% in the Wild Life Extreme Stress Test.

Finally, it needs to be said that the CPU stress tests are meant to push SoCs to their limits, so they are not representative of real-world, everyday use where most users will rarely push the Vivo X100 Pro this hard.