Intel i9-12900K Alder Lake Linux Performance In Different P/E Core Configurations

Written by Michael Larabel in Processors on 20 December 2021 at 02:00 PM EST. Page 1 of 7. 143 Comments.

One of the much requested Linux benchmarks since the debut of Intel Alder Lake last month has been for seeing the Core i9 12900K in different core configurations with its mix of P and E cores. Now that the Linux kernel activity has begun settling down around Alder Lake, here are those benchmarks for reference purposes with toggling Hyper Threading and different P and E core counts enabled.

The Core i9 12900K configurations tested under Linux for this article driven by reader requests and curiosity include:

8 P + HT + 8 E - The stock configuration of the Core i9 12900K with 8 P cores with HT enabled and then all 8 E cores, yielding the 16 core / 24 thread configuration of this flagship Alder Lake processor.

8 P + 8 E - All cores enabled, but disabling Hyper Threading.

8 P + HT - All P cores enabled with Hyper Threading on, but all E cores disabled.

1 P + HT + 8E - All E cores enabled but just 1 P core and HT enabled.

1 P + 8 E - All E cores enabled with just 1 P core enabled but HT disabled.

There isn't the ability to outright disable all P cores thus needing to test with at least 1 P enabled. Meanwhile all E cores can be disabled and in that configuration with many motherboards can allow enabling AVX-512 on Alder Lake. The cores were toggled via the UEFI BIOS.

The CPU was running at stock speeds during testing (contrary to the system table with Linux 5.15 reporting an incorrect turbo value as a known issue since fixed in Linux 5.16) with Noctua NH-U9S dual fan cooling. This ASUS ROG STRIX Z690-E GAMING WiFi system was running with 2 x 32GB DDR5-4400 Corsair memory and Radeon RX 6800 XT graphics. Linux 5.15 stable was used over Linux 5.16 Git since at the moment cluster-aware scheduling is still left enabled on 5.16 and that is negatively affecting Alder Lake performance while Intel is working on changes so it won't be enabled for ADL albeit they haven't yet landed. Thus for Alder Lake Linux users using the 5.15 kernel for now is recommended.

Intel Core i9 12900K Core Configurations Linux

Anyhow, for those curious about these core configuration tests, here is the data along with CPU power consumption numbers via PowerCap. The Phoronix Test Suite was also monitoring the CPU temperature as well during the individual benchmarks.

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