freebsd:tuning_power_consumption

差分

このページの2つのバージョン間の差分を表示します。

この比較画面にリンクする

両方とも前のリビジョン 前のリビジョン
最新のリビジョン 両方とも次のリビジョン
freebsd:tuning_power_consumption [2019-11-29 13:09]
Decomo 		freebsd:tuning_power_consumption [2019-11-29 19:32]
Decomo
行 229: 行 229:
  
 ==== 8. HDD ==== ==== 8. HDD ====
 +
 +まず、ありふれたオススメ設定は一時ファイル用にtmpfsを使う事です。RAMは消費電力へのインパクトが少なく、速く、
  
 First common recommendation is use tmpfs for temporary files. RAM is cheap, fast and anyway with you. Also you may try to setup automatic idle drive spin-down, but if it is the only system drive you should be careful, as every spin-up reduces drive's life time. For several months (until I have bought SATA SSD) I have successfully used SDHC card in built-in PCI sdhci card reader as main file system. On random read requests it is much faster then HDD, but it is very slow on random write. Same time it consumes almost nothing. USB drives could also be used, but effect is much less as EHCI USB controller consumes much power. Spinning-down my 2.5" Hitachi SATA HDD saves about 1W of power. Removing it completely saves 2W. First common recommendation is use tmpfs for temporary files. RAM is cheap, fast and anyway with you. Also you may try to setup automatic idle drive spin-down, but if it is the only system drive you should be careful, as every spin-up reduces drive's life time. For several months (until I have bought SATA SSD) I have successfully used SDHC card in built-in PCI sdhci card reader as main file system. On random read requests it is much faster then HDD, but it is very slow on random write. Same time it consumes almost nothing. USB drives could also be used, but effect is much less as EHCI USB controller consumes much power. Spinning-down my 2.5" Hitachi SATA HDD saves about 1W of power. Removing it completely saves 2W.
行 243: 行 245:
 ==== 10. USB ==== ==== 10. USB ====
  
 +以下のコマンドを実行することで、USBデバイスは個々に省エネモードの設定を切り替えることができます。
  
-USB devices can individually be switched to and from power save mode by running the following commands: +<code> 
- +# データが流れていない時にUSBデバイスを自動でサスペンドさせる
-# This command will enable automatic suspend of the USB device when no data traffic is pending.+
 usbconfig -d X.Y power_save usbconfig -d X.Y power_save
  
-# This command will disable USB power save for the given device.+# USBデバイスの省エネモード設定を無効にする
 usbconfig -d X.Y power_on usbconfig -d X.Y power_on
 +</code>
 +
 +デフォルト設定はUSB HUBを除いて全て「電源オン」です。
 +USBデバイスの省エネ設定を有効化する前に、USBデバイスのコンフィギュレーションデスクリプタの確認、すなわち''"bmAttributes"''フィールドでデバイスがリモート起動に対応しているか確認すべきです。
 +USBのサスペンド/レジュームによる遅延がUSB規格内に収まるよう、システムタイマーレートが250Hz未満でUSB省エネ設定をすることは非推奨です。
  
 The default for all devices except USB HUBs is power on. You should check the configuration descriptor of your device, that the "bmAttributes" field indicates that the device supports remote wakeup before enabling power save on a random USB device. It is not recommended to set the system timer tick rate below 250 HZ and enable USB power save, due to some USB suspend and resume delays which must comply to the USB specification. The power save feature also applies in the same way to USB device/gadget mode. The default for all devices except USB HUBs is power on. You should check the configuration descriptor of your device, that the "bmAttributes" field indicates that the device supports remote wakeup before enabling power save on a random USB device. It is not recommended to set the system timer tick rate below 250 HZ and enable USB power save, due to some USB suspend and resume delays which must comply to the USB specification. The power save feature also applies in the same way to USB device/gadget mode.
  • freebsd/tuning_power_consumption.txt
  • 最終更新: 2019-12-01 19:16
  • by Decomo