Microsoft’s new Surface with Windows RT tablet was the subject of a number of updates on its first-ever Patch Tuesday, but one of them really sticks out: Surface displays an unprecedented firmware update message in Windows Update, requiring users to plug in and charge the device before proceeding.

A note on the Surface support web site says that such updates are possible but doesn’t really explain further what’s entailed. “When a Surface hardware (also known as firmware) update is available, you’ll see a notification on your Surface,” the site explains. “When you get the notification, follow the on-screen instructions to update Surface using Windows Update.”

Right, thanks.

This week’s security bulletin doesn’t supply any information about the firmware update. And despite some blog reports to this effect, I’ve not seen any noticeable performance improvements related to app launching on my two Surface devices. Something tells me that Microsoft’s general description of firmware updates—that they “help improve stability and performance of PC hardware”—has triggered a bit of wishful thinking. But my own side-by-side tests with a patched and unpatched device showed no difference at all. (In fact, the unpatched one was sometimes faster, depending on the app.)

I’d ask Microsoft what’s improved, but they don’t respond to those kinds of requests these days. (Mary Jo Foley did ask and received no response.)