방금 MacBook Air에 Ubuntu 13.04를 설치했습니다. 기계가 느리게 느껴지는 동안 잠시 놀다가 CPU 주파수를 확인했습니다. cpufreq-info, 4 개의 코어 모두에서 800MHz (최저 설정)를보고합니다. 주지사는 주문형으로 설정되어 있습니다. 이제 시스템에 약간의 부하를 가하면 (4 번 해시하는 작은 스크립트를 실행) 기계가 멈추게되지만 cpufreq-info는 여전히 800MHz를보고합니다. 수동으로 주파수를 2GHz로 설정하면 성능 문제가 해결되지만 배터리 비용이 발생합니다.
이것은 cpufreq-info의 출력입니다.
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1 2 3
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 10.0 us.
hardware limits: 800 MHz - 2.00 GHz
available frequency steps: 2.00 GHz, 2.00 GHz, 1.90 GHz, 1.80 GHz, 1.70 GHz, 1.60 GHz, 1.50 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz, 1.10 GHz, 1000 MHz, 900 MHz, 800 MHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 800 MHz and 2.00 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz (asserted by call to hardware).
cpufreq stats: 2.00 GHz:5,75%, 2.00 GHz:0,47%, 1.90 GHz:0,00%, 1.80 GHz:0,01%, 1.70 GHz:0,01%, 1.60 GHz:0,01%, 1.50 GHz:0,01%, 1.40 GHz:0,01%, 1.30 GHz:0,01%, 1.20 GHz:0,02%, 1.10 GHz:0,01%, 1000 MHz:0,02%, 900 MHz:0,02%, 800 MHz:93,67% (1388)
analyzing CPU 1:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1 2 3
CPUs which need to have their frequency coordinated by software: 1
maximum transition latency: 10.0 us.
hardware limits: 800 MHz - 2.00 GHz
available frequency steps: 2.00 GHz, 2.00 GHz, 1.90 GHz, 1.80 GHz, 1.70 GHz, 1.60 GHz, 1.50 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz, 1.10 GHz, 1000 MHz, 900 MHz, 800 MHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 800 MHz and 2.00 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz (asserted by call to hardware).
cpufreq stats: 2.00 GHz:3,17%, 2.00 GHz:0,01%, 1.90 GHz:0,01%, 1.80 GHz:0,00%, 1.70 GHz:0,00%, 1.60 GHz:0,01%, 1.50 GHz:0,01%, 1.40 GHz:0,01%, 1.30 GHz:0,01%, 1.20 GHz:0,01%, 1.10 GHz:0,01%, 1000 MHz:0,02%, 900 MHz:0,02%, 800 MHz:96,71% (1433)
analyzing CPU 2:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1 2 3
CPUs which need to have their frequency coordinated by software: 2
maximum transition latency: 10.0 us.
hardware limits: 800 MHz - 2.00 GHz
available frequency steps: 2.00 GHz, 2.00 GHz, 1.90 GHz, 1.80 GHz, 1.70 GHz, 1.60 GHz, 1.50 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz, 1.10 GHz, 1000 MHz, 900 MHz, 800 MHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 800 MHz and 2.00 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz (asserted by call to hardware).
cpufreq stats: 2.00 GHz:2,69%, 2.00 GHz:0,00%, 1.90 GHz:0,01%, 1.80 GHz:0,01%, 1.70 GHz:0,01%, 1.60 GHz:0,02%, 1.50 GHz:0,01%, 1.40 GHz:0,01%, 1.30 GHz:0,02%, 1.20 GHz:0,02%, 1.10 GHz:0,01%, 1000 MHz:0,02%, 900 MHz:0,02%, 800 MHz:97,16% (1194)
analyzing CPU 3:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1 2 3
CPUs which need to have their frequency coordinated by software: 3
maximum transition latency: 10.0 us.
hardware limits: 800 MHz - 2.00 GHz
available frequency steps: 2.00 GHz, 2.00 GHz, 1.90 GHz, 1.80 GHz, 1.70 GHz, 1.60 GHz, 1.50 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz, 1.10 GHz, 1000 MHz, 900 MHz, 800 MHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 800 MHz and 2.00 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz (asserted by call to hardware).
cpufreq stats: 2.00 GHz:3,07%, 2.00 GHz:0,02%, 1.90 GHz:0,01%, 1.80 GHz:0,00%, 1.70 GHz:0,01%, 1.60 GHz:0,01%, 1.50 GHz:0,01%, 1.40 GHz:0,01%, 1.30 GHz:0,01%, 1.20 GHz:0,01%, 1.10 GHz:0,03%, 1000 MHz:0,03%, 900 MHz:0,01%, 800 MHz:96,77% (1004)
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq
같은 값을 다시 씁니까? 왜? 1을 쓰면ignore_ppc
값 이 변경됩니까? (PS 대신tee
또는>
대신을 사용할 수 있음dd
)