While camera and display haven’t always remained the strongholds of OnePlus, performance is one area where OnePlus phones have historically been quite good. So it came as a surprise when we learned that the company’s newest flagship, the OnePlus 9 Pro, isn’t pushing the envelope of performance that we have come to expect from OnePlus phones. On the contrary, the OnePlus 9 Pro seems to be performing worse in several popular apps than other Snapdragon 888-powered devices.

While running the performance benchmarks on the OnePlus 9 Pro, Andrei Frumusanu from AnandTech observed some rather odd behavior. When putting the device through the standard browser benchmarks such as Speedometer 2.0 and JetStream 2.0, the OnePlus 9 Pro posted surprisingly low scores, on par with budget devices released years ago. The OnePlus 9 Pro seems to be disabling the Cortex-X1 core when running these benchmarks. AnandTech further observed that the phone is also throttling the Cortex-A78 cores, and in subsequent benchmark runs, the workload is being completely isolated to the Cortex-A55 cores, resulting in unbelievably low scores.

In our review of the OnePlus 9 Pro, we didn’t notice this issue as we didn’t run standard benchmark apps or browser-based benchmarks. However, we can confirm the issue is present on our units, as the OnePlus 9 Pro running Google Chrome scores a measly 20.955 in JetStream 2 compared to the ZenFone 8’s 97.346 in the same test.

After a bit of digging, AnandTech discovered a OnePlus Performance Service that tracks when the user opens applications and decides whether or not to make modifications to the CPU scheduler. Many OEMs develop a similar kind of service and OS framework to control device performance, so its existence isn’t interesting in and of itself. What’s odd here is that OnePlus has several popular apps on the blacklist.

AnandTech was unable to find the exact list of applications affected by OnePlus’s performance-limiting mechanism, but they did test a handful of popular apps. Apps like Chrome, Twitter, Zoom, WhatsApp, Facebook, Instagram, Snapchat, YouTube, Discord, Microsoft’s Office apps, Firefox, Samsung Internet, etc., are affected. Surprisingly, OnePlus’ own first-party apps are affected as well. Luckily, this mechanism isn’t applied to popular games like Genshin Impact, and benchmark apps are also unaffected.

For what’s it worth, even with this performance-limiting mechanism in place, the OnePlus 9 Pro remains a fast and responsive phone. Most users won’t notice this behavior in day-to-day use as OnePlus has employed other mechanisms such as OS framework boosters and touch boosters to neutralize the effects of the performance-limiting mechanism. Andrei notes that he initially didn’t notice the issue until he compared his OnePlus 9 Pro side-by-side with his Galaxy S21 Ultra and Mi 11 Ultra.

GeekBench has delisted both the OnePlus 9 and OnePlus 9 Pro from their Android Benchmark Chart in response to this finding.

We have reached out to OnePlus for a comment on this matter and will update this post if we hear back.