Intel’s Emerald Rapids Xeon CPUs See 32% Boost & 18% Lower Power Consumption With A Small Patch

Intel's Emerald Rapids Xeon CPUs See 32% Boost & 18% Lower Power Consumption With A Small Patch 1

Intel's Emerald Rapids Xeon CPUs have received a free performance boost coupled with lower power consumption thanks to a new Linux patch.

Canonical Engineer Pedro Henrique Kopper recently sent a patch to LKML with the title 'Update Balance performance EPP for Emerald Rapids', which contained a small yet incredibly good tweak to improve the performance of Intel's Xeon datacenter CPUs in the Emerald Rapids lineup. The tweak is just a small change in the EPP(energy-performance_preference) value that increases the performance of these CPUs while maintaining better power efficiency.

By default, the EPP value shipped for the balance_performance is 128 but in an internal investigation held with Intel, the team found out that an EPP value set to 32 is more beneficial and suitable overall. In the patch, Pedro states "...,during an internal investigation together with Intel, we have determined that 32 is a more suitable value. This leads to significant improvements in both performance and energy".

The effect of this value change resulted in the following enhancements:

POV-Ray: 32% faster, 12% less energy

OpenSSL: 12% faster, energy within 1%

Build Linux Kernel: 29% faster, 18% less energy

Pedro adds, "Therefore, we should move the default EPP for balance_performance to 32. This is in line with what has already been done for Sapphire Rapids". This is surprising because the default EPP for balance_performance mode for the Sapphire Rapids was already set to 32 last year, resulting in drastic performance enhancements through a simple one-line code patch.

The Intel Emerald Rapids Xeon CPU series already exists in the market since December 2023 and this single-line code helped the Emerald Rapids CPUs gain a good performance boost. Meanwhile, it should be kept in mind that this performance uplift and decrease in energy consumption will only affect the out-of-the-box balance_performance mode being the default EPP on Ubuntu Linux and other Linux-based operating systems.

Users who switch to EPP modes like "performance" won't likely see such benefits but regardless, the EPP value 32 is surprisingly able to save more power compared to the EPP set at 128. Linux PM maintainer Rafael Wysocki is now reported to execute the implementation of this patch for the Linux 6.11 kernel in a week or two. This means systems using Emerald Rapids won't have to wait for the Linux kernel 6.12, which will have its merge window opened in September.

News Source: Phoronix