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Ramen_LadyHKG

Member

Registered: 2024-04-12

Posts: 5

My CPU (i7-8650U) cannot turbo boost exceed 2GHz ( Surface Book 2 )

A) Introduction
B) Details
C) Related Links

A) Introduction

Just like the title says, This CPU cannot turbo boost more than 2GHz, usually when it's under full load 100%.

But It's not caused by overheat throttling(on Linux, it's never exceeded 60degrees).
1) I used to suspect it was a Power Throttling issue but I've tried multiple tools and adjusted the power configuration, doesn't help at all.

(cpupower // tlp // thermald // throttled // power-profiles-daemon // intel-pstate // intel-rapl-msr  // x86-energy-perf-policy // s-tui // turbostat disable SecureBoot I still cannot get it working.)

This issue ONLY happens on Linux. All kernel version is affected.(stock, zen, surface).
On Windows, it can boost up to 4.2GHz and 35W without a problem.

------------ not important --------------
This issue has been troubling me for years.
Thanks to Linux not being resources hungry, I could tolerate it.

But with this low frequency, I cannot run a lot of games smoothly due to CPU bottleneck for GTX1060(Mobile), long compiling time.

Due to this issue not being Arch Specific, I didn't try here. Hopefully you guys wouldn't mind.

2) I've already reached out for help on multiple platforms Intel(Community,Emails,Discord), Microsoft(Emails), Reddit, Limmy, TechPowerUp,Github(linux-surface.
I've also made a bug report to Kernel bugzilla.

3) I've Arch, Fedora, Debian installed on my system; I've also tested these distro in Live Environment (Mint, MX, Ubuntu, Nobara, Garuda, CachyOS...) but they all suffer the same issue.

------------ not important --------------

B) Details

Essentially, If I run heavy CPU process(80%), the CPU will throttle down from 2GHz to 1.5GHz or less. (https://github.com/erpalma/throttled says it's current throttling)

4) I tried to run test with stress-ng, s-tui and noticed it's when all cores at high utilization, the CPU throttles.

As shown above, all 8 cores is stressed with s-tui. And when the CPU is limited below 10W Pkg, 1.3GHz while temp not higher than 55C.

On Windows though, the CPU can be function just fine. I use ThrottleStop to limit PL1:22W, PL2:30W

5) I've tried kernel parameters for Intel-pstate from https://wiki.archlinux.org/title/CPU_frequency_scaling#Scaling_drivers.
Active, HWP mode no changes; Passive or disable though, the CPU can boost up to 2.1GHz for a long time but that just it.

6) I've read about MSR, MMIO topics but I think cpupower, intel-rapl combines is doing similar things.

7) I began to suspect It's M$ doing stuff to limit Linux but another Surface Book 2 user who has i5-7300U does not face the same issue I've.

8) I've found multiple cases related to this Intel line processor (Kaby Lake Refresh)[Covering i7-8650u, 8550u, 8665u] on multiple platforms(DELL,Thinkpads..).
https://askubuntu.com/questions/1328008 … untu-20-04
https://askubuntu.com/questions/1329587 … untu-20-04
https://chat.stackexchange.com/rooms/12 … and-igntec

Related Links

9) This is the Surface Kernel Github repo, I opened the first post here
https://github.com/linux-surface/linux- … ssues/1041

10) I've contacted Intel & Microsoft but they either say it's OEM issue or Linux issue. They weren't helpful at all.
https://community.intel.com/t5/Processo … 828#M67367

11) This is the kernel bugzilla report I made
https://bugzilla.kernel.org/show_bug.cgi?id=218212

12) I tried to reached out on other wider platforms but didn't get many answers
https://lemmy.world/post/8883518
https://www.reddit.com/r/linux4noobs/co … /?sort=new
https://www.techpowerup.com/forums/thre … pt.316202/

This is the performance we can normally get:
https://www.reddit.com/r/SurfaceLinux/c … an_get_on/
https://www.reddit.com/r/Surface/commen … cinebench/d4u

Last edited by Ramen_LadyHKG (2024-04-22 14:59:57)

Ramen_LadyHKG

Member

Registered: 2024-04-12

Posts: 5

Re: My CPU (i7-8650U) cannot turbo boost exceed 2GHz ( Surface Book 2 )

Hopefully these are enough to covered the issue.
If not I can provide as much as i can. Thank you

I was a little rude dealing with M$, Intel staff. I am sorry
I will try to be more helpful and patient here.

Hopefully we can come up with a solution and help others who suffer the same.

Ramen_LadyHKG

Member

Registered: 2024-04-12

Posts: 5

Re: My CPU (i7-8650U) cannot turbo boost exceed 2GHz ( Surface Book 2 )

exactly like this

https://bbs.archlinux.org/viewtopic.php … 8#p2166298

Last edited by Ramen_LadyHKG (2024-04-21 20:27:57)

Ramen_LadyHKG

Member

Registered: 2024-04-12

Posts: 5

Re: My CPU (i7-8650U) cannot turbo boost exceed 2GHz ( Surface Book 2 )

https://askubuntu.com/questions/1329587 … untu-20-04

MS-DTYP

Member

Registered: 2020-05-01

Posts: 28

Re: My CPU (i7-8650U) cannot turbo boost exceed 2GHz ( Surface Book 2 )

1. Have you updated your firmware with fwupd (including Intel ME) and also microcodes?

2. Your Linux kernel version is outdated today.

3. Why are you using ThrottleStop on Windows? I think you should compare clean Windows and clean Linux benchmarks, without any 3-rd party software.

Last edited by MS-DTYP (2024-05-06 13:19:27)