Intel® AMT, ME, MEI, and Windows* Instant On/Connected Standby

Back in the old days, one only needed to think about ME (Intel® Manageability Engine) Firmware if one was using Intel® Active Management Technology (AMT) on Intel® vPro™ Technology systems.  But some form of ME is now found on most Intel client architecture based systems including the need for an interface driver between the OS and the hardware (previously called HECI, now called the MEI (Manageability Engine Interface) driver.)  You can check the version of your MEI driver under Device Manager > System Devices > Intel Management Engine > right click Properties and look at the driver tab.

But don't let the name fool you, ME Firmware does a lot more than manageability.  

For this blog, I want to mention a few recent features and which versions provide them. The features I'll mention are: 

Microsoft Connected Standby exists to save power while maintaining network connectivity. It can be triggered by closing the lid, pressing the power button or when a system goes idle. The user sees the screen go off and software is throttled or suspended, but connectivity is maintained. The power requirement for certification is that the battery drop less than 5% over 16 hours in CS state. To maintain connectivity, the network adapter (wired or wireless) must accept ARP requests without waking the host. (For the technically curious, the CS power states are called SOi (1-3) and are a combination of Cx (cpu state) and RTDx (device state)).  All Windows* 8.x client versions support CS but require the BIOS be configured for CS. Intel ME firmware support for CS is limited to ME 9.5 and ME 10 on Windows 8.1 (64-bit) in the consumer SKU although power gating is already available in both consumer and corporate (pre AMT enabled) SKUs.  FPrior to Windows CS, Intel had a similar feature called Intel® Smart Connect Technology, (does not coexist on a system with CS). CS systems maintain network connectivity while Smart Connect systems would wake and check periodically. 

Now we know that for Intel AMT, ME has it's own power states outside of the OS so that it can be managed/contacted out of band; and since the OS does not control the ME states, they are handled as S0 states. Plus we must remember that wired and wireless are handled differently by ME for that OOB connectivity. Wired adapters have two drivers used - one for the OS and another for the ME. But with wireless, the OS and ME share a driver, which cannot be used simultaneously by both.  So in AMT 9.x and 10.0, the CS power requirement cannot be met when AMT is enabled, something that will change in some future versions. Part of enabling AMT while using CS comes from the Intel ME Power Gating feature, which as you might have guessed, currently works with consumer firmware and non configured AMT corporate firmware. Note: SOL is hidden from the OS when AMT is not provisioned. The driver is usually preinstalled, but SOL won't be seen until the system is provisioned and rebooted. 

A word about versioning here. Intel has been striving to make firmware versions backward compatible and also split the firmware into 2 sizes. There's a small version for consumer systems and a larger version for corporate systems. The corporate larger AMT SKU can be paired with Intel vPro Technology Core processors for all the vPro technology features.  However AMT features can exist in client and/or corporate, but tend to vary across OS. 

Likewise is previous versions, the ME FW version number was usually one integer higher than the chipset version. Intel 8 series chipsets used ME 9.0. But in moving to backward compatibility as well as addressing the socket sharing between CPU generations, this versioning scheme was modified. The 9 series (2 chip) chipsets used 9.1 firmware  with 9.0 being field upgradable to 9.1. And then came 9.5 and 10.0.  Starting with 9.0, each release should be applicable to any ME 8.x or later system. (One installer will determine which features to install). I checked my versions and on my Intel 7 series chipset system ,I am running the 9.5 MEI driver.

Important Note: ALWAYS use the ME firmware supplied by your motherboard manufacturer and the MEI driver supplied.

You can check for Instant On support by typing powercfg /a at the command prompt.

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