Intel Core Ultra 9 285K gains performance uses less power in Linux
Phoronix has revisited Intel’s Core Ultra 9 285K “Arrow Lake” desktop CPU on Linux, one year after launch. In more than 240 tests, the chip now delivers about 9% higher performance compared to October 2024 , while average CPU power usage fell from 136W to 116W, roughly 85% of the original level.
The retest keeps the hardware configuration unchanged. Phoronix used the same Core Ultra 9 285K, ASUS ROG MAXIMUS Z890 HERO motherboard, 2 x 16 GB DDR5-6400 memory, and a Radeon RX 7900 GRE graphics card. The only changes are on the software side: the original testing used Ubuntu 24.04 LTS with a Linux 6.10 kernel, GCC 13.2, and Mesa 24.2, while the new run uses Ubuntu 25.10, Linux 6.18 Git, GCC 15.2, and Mesa 25.2.
Source: Phoronix
Web workloads show some of the biggest gains. Firefox benchmarks such as Speedometer, Octane, and Jetstream all scale up on the newer stack, helped by browser updates and kernel work around Arrow Lake’s P and E core scheduling. Power draw during these browser tests is also lower than at launch.
Source: Phoronix
The improvements extend to code compilation, content creation, HPC workloads, media encoding, and AI speech tests like Whisper.cpp, with most result charts favoring the November 2025 setup. The geometric mean of all benchmarks lands at a 9% uplift, while average CPU power drops by about 20W, and peak power remains in the same 250 W range. According to Phoronix, this is due to Intel Linux’s continuous efforts to improve hybrid core behavior and tools like Thermald, which gradually increase Arrow Lake efficiency.
Source: Phoronix
