Trying The Turbo Boost Max 3.0 Patches On Linux 4.9 With A Core i7 6800K Broadwell-E
Written by Michael Larabel in Linux Kernel on 24 October 2016 at 09:29 AM EDT. 30 Comments
Last week the Intel Turbo Boost Max 3.0 patches were updated for the Linux 4.9-rc1 kernel. While it won't be mainlined until Linux 4.10 at least, I decided to try out these TBM 3.0 / ITMT patches with a Core i7 6800K Broadwell-E CPU.

Turbo Boost Max 3.0 Technology is designed to boost single-threaded application performance by moving the most critical workloads to the fastest core. TBM 3.0 is complementary to TBM 2.0. Those unfamiliar with it can find details at

While CPUs with Turbo Boost Max 3.0 have been shipping for months, there hasn't been any mainline support yet. But I patched an otherwise 4.9-rc1 vanilla kernel with these patches and enabled CONFIG_SCHED_ITMT for having a kernel with the needed support. The Core i7 6800K used for testing has a 3.4GHz base frequency, 3.6GHz turbo frequency, and a Turbo Boost Max Tech 3.0 frequency of 3.8GHz. The ITMT appears just short for Intel Turbo Max Technology.

The TBM 3.0 support on a supported kernel can then be toggled via /proc/sys/kernel/sched_itmt_enabled.

In early benchmarks done though of (mostly single-threaded) workloads, there wasn't any real difference found in performance.

Anyhow, will try more TBM 3.0 patches once the patches are deemed ready for mainline and ideally by then will be able to get access to more Turbo Boost Max 3.0 processors.
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Michael Larabel is the principal author of and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and automated benchmarking software. He can be followed via Twitter or contacted via

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