Surface

Hibernate

The Surface power plan (Balanced) doesn’t expose hibernate settings by default, but we can add them.

This disables hibernate while plugged in, and enables after 30 mins on battery to avoid being disabled by default

powercfg /setdcvalueindex scheme_current sub_sleep hibernateidle 0
powercfg /setacvalueindex scheme_current sub_sleep hibernateidle 1800

TODO external Windows Hello webcam regkeys (ESS etc)

Wake-on-Power

Wake-on-Power for Surface devices

Some Surface firmware versions support wake from sleep or hibernate when power is provided. This could be very useful for connecting closed laptops to a dock, but I’m not sure whether it works with USB-C or just Surface Connect. It’s also off by default and needs to be enabled with SEMM or DFCI. Unfortunately neither is supported for my consumer AMD Surface Laptop 3, so I’ve been unable to test.

DFCI requests use a mailbox design, where payloads are set in the UEFISettingsRequest UEFI variable and results are set in UEFISettingsResponse. Payloads can be signed, particularly for SEMM, so UEFISettingsResponse defaults to the signature header MSSA.

A full list of variables is available with

Install-Module UEFIv2
$vars = Get-UEFIVariable -All | select *,@{n="Value";e={$_ | Get-UEFIVariable}}

This can be compared against a DFCI test payload.

manager: MS Settings Manager {
  SettingProviders {
	shape: document
  }
  MsXmlSupportLib
}
MsPermissionProtocol <-> manager <-> MsAuthProtocol
 
tools: Tools / External {
  shape: cloud
}
req: UEFISettingsRequest Var {
  shape: oval
}
tools -> req -> manager
 
res: UEFISettingsResult Var {
  shape: oval
}
manager -> res -> tools

Storage

Upgraded my Surface Laptop 3 to a Micron Crucial 2400 1TB

Before:

After:

TODO cooling upgrade Fixed Surface Laptop 3 overheating issue : r/Surface (reddit.com)