CPU Turbo mode

TL;DR:

Problem: Laptop gets hot and fan is too loud

Solution: In cmd.exe terminal execute following three commands

Enable the PERFBOOSTMODE option of Windows power plan:

reg.exe ADD "HKLM\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\be337238-0d82-4146-a960-4f3749d470c7" /v Attributes /t REG_DWORD /d 2

Disable the CPU Turbo mode in the currently used Windows power plan in plugged-in state and on battery power:

FOR /F "tokens=4" %i IN ('powercfg.exe /setactivescheme') DO powercfg.exe /setacvalueindex %i SUB_PROCESSOR PERFBOOSTMODE 0
FOR /F "tokens=4" %i IN ('powercfg.exe /setdctivescheme') DO powercfg.exe /setacvalueindex %i SUB_PROCESSOR PERFBOOSTMODE 0

The CPU Turbo mode has following names across CPUs:

• AMD PowerNow!
• AMD Turbo Core
• AMD Core Performance Boost (CPB)
• AMD Precision Boost Overdrive
• AMD Precision Boost 2
• Intel Geyserville
• Intel SpeedStep, Enhanced SpeedStep (EIST)
• Intel Speed Shift Technology (SST)
• Intel Turbo Boost
• Intel Turbo Boost Max 3.0 Technology
• dynamic overclocking
• dynamic frequency scaling
• dynamic voltage and frequency scaling (DVFS)

The narrative

I put my hands on a new laptop, rather top shelf. End of the year holiday season is a good time to rest so I visited GOG¹ and returned to the Heroes of Might and Magic 3², a timeless masterpiece. The gaming session was great… for an hour. After that I woke my spouse up, with the sound of the CPU fan. Indeed, the game was playing smooth and pleasant but the fan and all the heat and the battery life, all went to crazy levels. I made a round of typical hardware, firmware and software solutions which didn’t yield desired results so I dig in.

Vendor

First the manual³. It states that pressing Fn+F8 can alleviate load on the CPU. There’s even such funny statement:

Note: In balanced mode or best-performance mode, avoid keeping your hands, your lap, or any other part of your body in contact with a hot section of the computer for 10 seconds or longer.

Pressing the keyboard key result is visible by Windows 11 Power & battery Power Mode setting toggle. Alas, the Best Power Efficiency mode didn’t do much.

Windows 11, Settings, Power & battery, Power Mode

However the manual mentions the Cool and Quiet on lap BIOS setting as well. That sounds like exactly the thing that I wanted to address, the hot and loud on lap laptop. The Internet wisdom says it can turn 5h battery life into 7h battery life. It didn’t help in my case though. There’s nothing more in the Lenovo BIOS for the Thinkpad regarding power or battery management, it’s bare bones BIOS.

I’ve searched a little in the vendor tools and found a few of them which sounded like something which can fix the problem. There’s Lenovo Vantage⁴ boasting with Optimal Battery Performance handling, sadly its Power settings aren’t helpful. Then there’s the tailored to my needs Lenovo Performance Tuner⁵,⁶ which is meant to “Get the Most Out of My Workstation”. It has interesting features: can ask the operating system to change CPU priority and CPU affinity of a process, something achievable with the Windows Task Manager but more permanent. CPU priority and CPU affinity didn’t help me though. There’s no possibility to do anything else with the Lenovo software, the overclocking features are not available to the “mobile” flavour of CPUs.

Lenovo Performance Tuner

Foundry

Off to the CPU manufacturer tools. There’s AMD Software: Adrenalin Edition⁷ with the AMD Radeon Chill and other features, but they are either disabled or just unhelpful. There’s AMD Ryzen Master⁸ which might have helped me, but it doesn’t support the processor. I made a detour to an open source alternative RyzenAdj⁹ which was created for this specific use case - to support CPUs not supported by Ryzen Master - maintained in a typical open source way with reverse-engineering and with gathering information from AMD BIOS and kernel developer's guide¹⁰, with a myriad of UI apps on top, but for now I don’t want to try a tool which can brick my device and make the warranty void.

AMD Ryzen Master error

So back to the CPU documentation. On page 657 and 659 of the AMD64 Architecture Programmer's Manual, Volumes 1-5¹¹, chapter 17 Hardware Performance Monitoring and Control, there’s the passage:

The AMD64 architecture provides several mechanisms by which software can monitor and control processor performance to optimize power use. […] Core performance boost (CPB) dynamically increases core clock rate beyond that defined for the P0 power state to achieve higher performance while maintaining power consumption below a preset level. […] CPB ensures that average power consumption over a thermally significant time period remains at or below the defined power limit.

Hm. Sounds like the thing.

Platform

A little bit of googling around and the server-related Power and performance tuning¹² Microsoft documentation sheds more light on the Power plans, powercfg.exe and the UI version of it. It turns out that there’s no Windows 11, 10 or 8 UI for the power plans but the good old Control Panel with Windows 7-like UI contains the Control Panel\Hardware and Sound\Power Options\Edit Plan Settings editable power plans. Playing with the Processor power management’s Maximum processor state and Minimum processor state and even setting it to ridiculously low values doesn’t help with my issue, however I can see it does change the way the power consumption behaves. But nothing about turbo. And then the knowledge of the Internet reveals that Microsoft wanted to save unsuspecting users from breaking their machines and thus hid the Turbo setting - and it backfired. There’s a need to unhide and enable the setting by Windows registry, as described in the TL;DR: section above. Once that’s done the following Processor performance boost mode option with a set of values appears¹³:

Windows 11, Control Panel, Hardware and Sound, Power Options, Edit Plan Settings

And it did work. Disabling it made the computer use 3.5 Watts instead of 18 Watts.

Let that sink in: 3.5 W instead of 18 W.

In the knowledge gathering and tuning process I also used a number of old performance monitoring friends: CPU-Z¹⁴, HWiNFO¹⁵. Below you can see the Wattage and CPU temperature (no fan controller available so no sound dB graph nor revolutions per minute) when running HoMM3 on CPU, first with Turbo on battery and later plugged in; then on CPU without boost first plugged in and later on battery:

HWiNFO, running Heroes of Might and Magic III, CPU with boost

HWiNFO, running Heroes of Might and Magic III, CPU without boost

Mods

And that would be it. But then I made another birds eye view and asked, how does the HoMM3 community fare with the issue. The answer was modding with HD+ mod¹⁶. It has the Sys.CPU.ReduceUsage=2 option which fixes my issue. But the mod is closed source, it’s homepage looks fishy, it’s a very heavy mod while - given the description of the mod’s configuration option - the fix is lightweight. Fortunately there’s also the lightweight HeroesGL mod which ports Heroes of Might and Magic 1, 2, 3 and 4 from DirectDraw to OpenGL and as a side fix it also hooks into the DDraw.dll and adds this tiny elegant fix¹⁷:

BOOL __stdcall PeekMessageHook(LPMSG lpMsg, HWND hWnd, UINT wMsgFilterMin, UINT wMsgFilterMax, UINT wRemoveMsg)
{
  if (PeekMessage(lpMsg, hWnd, wMsgFilterMin, wMsgFilterMax, wRemoveMsg))
    return TRUE;

  if (config.coldCPU)
    Sleep(1);

  return FALSE;
}

I’ve tried it on the GOG version of HoMM3 but it didn’t work due to the recent 2024-11-13 change which adds another level of indirection to the DDraw.dll with the DDrawCompat¹⁸. Thankfully the GOG distributes the game with two binaries: Heroes3.exe which uses the DDrawCompat and H3Blade.exe which uses original DDraw.dll. And the above code of the HeroesGL does fix the game run with the H3Blade.exe executable:

HWiNFO, running Heroes of Might and Magic III with HeroesGL fix, CPU regardless of boost

Non-closing words

I really like the way the HeroesGL works, the source code is available on GitHub, with MIT license and it’s clean. I’d like to contact and express my gratitude to the author of the mod, Oleksiy Ryabchun. And here the real world kicks in. The binary version of the mod which I got from someone’s Google Drive¹⁹,²⁰ (VirusTotal is kind of OK with it²¹) was created 2022-01-05. Soon after the personal webpage of the author was collected by the Wayback Machine on 2022-01-20 and it archived the content, but on 2022-03-02 the page was empty²² and the author is silent since then. Since the invasion.

And it struck me, wondering how to redeem the non ideal world. Maybe paying due respect to works of persons such as Maria Primachenko²³ and more generally the Library Of Ukrainian Art²⁴ would offset the damage, even if by tiny bit. Her works fit the HoMM esthetics.

Heroes of Might and Magic: A Strategic Quest, Castle Ironfist campaign map by Maria Primachenko

Heroes of Might and Magic: A Strategic Quest, Sorceress troops, Phoenix by Maria Primachenko

Heroes of Might and Magic III, Castle troops, Cavalier by Maria Primachenko