title: How to turn off "REAL" PCIe power for a GPU device on Llinux
body: <p>I want to turn off "REAL" PCIe power for a GPU device on Linux.
  I found some home pages, but they could not cut the "REAL" power.</p>
  
  <p>I monitored the AC power usage, but all of them could not cut the real power usage. Could you tell me how to turn off PCI power for a device?</p>
  
  <p>The followings are the methods I tired.</p>
  
  <p>Method.1</p>
  
  <pre><code>Turn off
  # echo "0" &gt; /sys/bus/pci/slots/"SLOT No."/power
  turn on
  # echo "1" &gt; /sys/bus/pci/slots/"SLOT No."/power
  </code></pre>
  
  <p>Method.2</p>
  
  <pre><code>Unbind. 0000:0c:00.0 is device ID.
  # echo -n "0000:0c:00.0" &gt; /sys/bus/pci/drivers/"DEVICE NAME"/unbind 
  Bind.
  # echo -n "0000:0c:00.0" &gt; /sys/bus/pci/drivers/"DEVICE NAME"/bind 
  </code></pre>
  
  <p>Method.3</p>
  
  <pre><code>Remove. 0000:0c:00.0 is device ID.
  # echo "1" &gt; /sys/bus/pci/devices/0000\:0c\:00.0/remove 
  Recover.
  # echo "1" &gt; /sys/bus/pci/rescan
  </code></pre>
  
  <p>I confirm that ASPM (Active State Power Management) is supported on the BIOS and effective on Linux. The Linux is booted with "pcie_aspm=force" kernel option.</p>