CPU 频率在负载下下降，没有散热问题

Question

这个问题困扰了我几个星期，我似乎无法弄清楚真正的问题可能是什么。

问题是 CPU 频率在负载下急剧下降。我的意思是，例如，当打开网络浏览器时，CPU 频率约为 400 MHz，而当没有负载时，频率会回升。（不是很高，但仍然不是静态行为）。这真的让我发疯。

一些可能有帮助的进一步信息：

硬件：

联想thinkpad T15：

CPU：英特尔I7-10510U

=> 基本时钟：1.8GHz

=> 升压时钟：4.9GHz

软件：

发行版：Ubuntu 20.04.1 LTS

内核：5.4.0-52-generic

?  cpupower frequency-info
analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency:  Cannot determine or is not supported.
  hardware limits: 400 MHz - 4.90 GHz
  available cpufreq governors: performance powersave
  current policy: frequency should be within 400 MHz and 4.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 1.24 GHz (asserted by call to kernel)
  boost state support:
    Supported: yes
    Active: yes

# command to simulate a stress on the CPU
?  stress-ng --cpu 8 --timeout 15s
stress-ng: info:  [43652] dispatching hogs: 8 cpu
stress-ng: info:  [43652] successful run completed in 15.34s

# The result of the stress on the CPU
?  sudo turbostat --Summary --quiet  --show Busy%,Bzy_MHz,PkgTmp,PkgWatt,GFXWatt,IRQ --interval 6
Busy%   Bzy_MHz IRQ PkgTmp  PkgWatt GFXWatt
6.58    1862    11418   51  5.00    0.00
7.69    1813    14444   51  4.96    0.00
7.79    1817    16988   51  5.03    0.00
7.99    1724    14679   51  5.00    0.00
9.12    1542    14504   51  4.91    0.00
8.82    1662    13878   51  4.98    0.00
60.61   1060    19508   52  5.84    0.00 # Applied load around here
99.75   460     19984   51  4.59    0.00
98.06   654     21316   51  4.79    0.00
10.26   1181    16730   51  4.25    0.00 # load ended around here
5.90    1782    10315   50  4.74    0.00
6.60    1890    11701   50  5.10    0.00
6.00    1901    10736   50  5.13    0.00
6.74    1981    13477   51  5.23    0.00
7.43    1731    1500    50  4.92    0.00

?  cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 4294.55 ms.
  hardware limits: 400 MHz - 4.90 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 4.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 1.26 GHz.
analyzing CPU 1:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 1
  CPUs which need to have their frequency coordinated by software: 1
  maximum transition latency: 4294.55 ms.
  hardware limits: 400 MHz - 4.90 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 4.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 1.48 GHz.
analyzing CPU 2:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 2
  CPUs which need to have their frequency coordinated by software: 2
  maximum transition latency: 4294.55 ms.
  hardware limits: 400 MHz - 4.90 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 4.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 982 MHz.
analyzing CPU 3:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 3
  CPUs which need to have their frequency coordinated by software: 3
  maximum transition latency: 4294.55 ms.
  hardware limits: 400 MHz - 4.90 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 4.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 983 MHz.
analyzing CPU 4:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 4
  CPUs which need to have their frequency coordinated by software: 4
  maximum transition latency: 4294.55 ms.
  hardware limits: 400 MHz - 4.90 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 4.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 1.06 GHz.
analyzing CPU 5:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 5
  CPUs which need to have their frequency coordinated by software: 5
  maximum transition latency: 4294.55 ms.
  hardware limits: 400 MHz - 4.90 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 4.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 872 MHz.
analyzing CPU 6:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 6
  CPUs which need to have their frequency coordinated by software: 6
  maximum transition latency: 4294.55 ms.
  hardware limits: 400 MHz - 4.90 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 4.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 926 MHz.
analyzing CPU 7:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 7
  CPUs which need to have their frequency coordinated by software: 7
  maximum transition latency: 4294.55 ms.
  hardware limits: 400 MHz - 4.90 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 4.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 850 MHz.

到目前为止我尝试过的事情：

• 将功率调节器设置为性能
• 设置 intel pstate 驱动程序频率限制
• 使用 cpupower 设置频率限制（这是否与直接更改 intel pstate 驱动程序值相同？）
• 重新安装 ubuntu 20.04，在全新安装时遇到同样的问题。

我曾经让我的系统像它应该的那样启动并运行：从 Windows 重新启动后，当在系统上运行假负载时，CPU 直接达到最大 CPU 限制，并在一天的剩余时间里继续工作。系统热像预期的那样受到限制，但据我所知从未低于 2 GHz。但是，重新启动后问题再次出现......之后我也无法重现这种行为......

如果还不清楚：问题是如何解决这个问题，以便我可以充分利用笔记本电脑的潜力，而不是每次加载新窗口或打开新的浏览器标签时都等待？

提前致谢！

编辑：

• 添加重新安装到我尝试过的东西

Answer 1

事实证明这是一个散热问题，但与软件无关。将设备送回工厂后，他们更换了设备的冷却器，问题得到解决！

显然，CPU 温度升至略低于 100 摄氏度，然后立即进行热节流。