Linux Patch Boosts Intel 5th Generation Xeon "Emerald Rapids" Performance by up to 38%, up to 18% Less Power

[AleksandarK]

Intel's 5th generation Xeon Scalable processors codenamed Emerald Rapids, have been shipping since late 2023 and are installed at numerous servers today. However, Emerald Rapids appears to possess more performance and efficiency tricks than it initially revealed at launch. According to the report from Phoronix, reporting on a Linux kernel patch sent to the Linux Kernel Mailing List (LKML), there is a chance for up to 38% performance increase while using up to 18% less power on all Intel 5th generation Xeon machines. Thanks to Canonical (maker of Ubuntu Linux) engineer Pedro Henrique Kopper, who explained the patch on the LKML, we found out that changing a single line of code yielded this massive increase.

Ubuntu Linux, as well as many other distributions, ship with Energy Performance Preference (EPP) for Emerald Rapids with a "balance_performance" value of 128. However, changing the value to 32 now yields a massive performance improvement alongside using less power. The EPP "balance_performance" is the default out-of-the-box setting for many Linux distributions. Users manually setting the "performance" mode in the EPP are not expecting any increase from this patch, as the "balance_performance" mode had issues balancing power and efficiency. Introducing this new setting yields more performance for machines that run at default settings, and this is especially important for data centers where the need for lower power and increased performance is constantly surging. Especially at hyperscalers like Amazon, Google, and Meta, which may run tens of thousands of these CPUs at default settings to keep them stable and well-cooled, who can now enjoy a massive performance increase with less power consumed.



Below, you can see the patch quote as well as more performance/power measurements.

On Intel Emerald Rapids machines, we ship the Energy Performance Preference (EPP) default for balance_performance as 128. However, 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:

POV-Ray: 32% faster | 12% less energy
OpenSSL: 12% faster | energy within 1%
Build Linux Kernel: 29% faster | 18% less energy

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.

View at TechPowerUp Main Site | Source

 

[Blurpy]

These gonna kill themselves as well

 

[ZoneDymo]

I mean that is excellent, but, I think with improvements that large it was probably just really poorly setup before.
Bit like this massive 500% gains via a driver update with Intel Arc in the past.

 

[stimpy88]

It amazes me that Intel themselves didn't see this... But we all know they are not what they used to be.

 

[FoulOnWhite]

Changing a single line of code yielded this massive increase.

Someone made a booboo

But nice increase in performance, and nice decrease in power use.

 

[Caring1]

Can this also affect how current consumer Intel CPUs run in Ubuntu or other Linux variants?
Looking at this, it has EPP set to Performance.

14900k.9 Benchmarks [2402255-NE-14900K93584] - OpenBenchmarking.org

openbenchmarking.org

 

[Wirko]

It amazes me that Intel themselves didn't see this... But we all know they are not what they used to be.

Any company that deploys megawatts upon megawatts of silicon does an immense amount of validation, they have probably already found and optimised the non-optimum settings for themselves.

 

[stimpy88]

Any company that deploys megawatts upon megawatts of silicon does an immense amount of validation, they have probably already found and optimised the non-optimum settings for themselves.

Selfish that they didn't share the fix then. I thought that was Linux was supposed to be all about?

 

[phints]

Unfortunately this is buried deep within the kernel, so most distros won't even have it updated for a while. It won't be out until a future kernel 6.11 rev, or possibly not until 6.12. Update your kernels people.

I noticed Alder Lake is still set at EPP 102, I wonder if someone has checked all of these. Intel should be jumping on this, their chips have been known for poor efficiency for years they should be on top of this.

 

[phanbuey]

linux power management is to this day the reason why linux laptops are not a thing.

 

[Solaris17]

Selfish that they didn't share the fix then. I thought that was Linux was supposed to be all about?

They actually did. That epp value was already set for sapphire rapids.

 

[Darmok N Jalad]

linux power management is to this day the reason why linux laptops are not a thing.

But is that because of Linux PM or x86? Android has a Linux kernel, as do many other things, but they don't use x86. I'm curious to see how Linux behaves on snapdragon laptops, as that's probably the best way to find out.

 

[phanbuey]

But is that because of Linux PM or x86? Android has a Linux kernel, as do many other things, but they don't use x86. I'm curious to see how Linux behaves on snapdragon laptops, as that's probably the best way to find out.

Considering there's not even a stable release out for them yet despite long-running ARM support on the kernel, I don't imagine it will be good. I know theres a bunch of teams working on it now. Someone on youtube compiled a beta kernel for them a few weeks agoa to run some benchies, but I havent heard anything since.

 

[remixedcat]

linux power management is to this day the reason why linux laptops are not a thing.

just for suspend/standby there's a command line fix I'll update the post when I find it.

The rest you can just change CPU governor like this

I got it set to this most of the time... and sometimes put on powersave when I am on battery but a lot of the time this is plugged in...

 

[phanbuey]

just for suspend/standby there's a command line fix I'll update the post when I find it.

The rest you can just change CPU governor like this

I got it set to this most of the time... and sometimes put on powersave when I am on battery but a lot of the time this is plugged in...

View attachment 357609

Not just - getting the battery calibrated, and the percentage to display correctly, getting the power settings dialed in through TLP, god help you if your manufacturer didn't make a custom ACPI module - because your laptop will just straight turn off when it thinks it has 30% battery remaining. Suspend and standby... just pain all around - not surprising to see it takes a bunch of expertise and special settings on the server side.

Windows Server you can kind of just roll your face on the keyboard during setup and get the consistent mediocre performance we know and love.

 

[NoneRain]

Not just - getting the battery calibrated, and the percentage to display correctly, getting the power settings dialed in through TLP, god help you if your manufacturer didn't make a custom ACPI module - because your laptop will just straight turn off when it thinks it has 30% battery remaining. Suspend and standby... just pain all around - not surprising to see it takes a bunch of expertise and special settings on the server side.

Windows Server you can kind of just roll your face on the keyboard during setup and get the consistent mediocre performance we know and love.

best comment.

 

[unwind-protect]

Translation: Ubuntu cripples performance with their default settings.

 

[Solaris17]

Translation: Ubuntu cripples performance with their default settings.

Linux kernel patch sent to the Linux Kernel Mailing List

Ubuntu Linux, as well as many other distributions

However, during an internal investigation together with Intel, we have determined that 32 is a more suitable value.

You mean when Ubuntu fixed it by sending a patch to the KERNEL. Lets try not to spread so much FUD.

 

[unwind-protect]

Oops. Sometimes I get carried away with the reflexive Ubuntu bashing.