Once again, Microsoft has provided important firmware updates for its Surface tablets in tandem with its monthly Patch Tuesday updates. There are a couple of Windows 8.1 Preview updates available as well.

I didn’t cover July’s Surface firmware updates explicitly because there was only one, to Surface RT that enhanced system performance and reliability. Most of these monthly updates have been more substantial. But this month, only Surface Pro has been updated.

Here’s what’s been added in this month’s updates.

Surface RT firmware improvements

Update includes these firmware and performance improvements:

UEFI. A Unified Extensible Firmware Interface (UEFI) firmware update that optimizes the audio experience at low volumes and removes a perceived pulsing in audio volume for some content

Drivers. An update to system drivers that enhance stability and reliability.

Surface Pro firmware improvements

Update includes these firmware and performance improvements:

UEFI/SAM. A UEFI and System Aggregator (SAM) firmware update that enhances system stability, reliability, reduces power consumption, and improves touch latency with the touchpad on the Surface Type Cover and Surface Touch Cover.

One more important note: These updates only apply to those Surface users on the original shipping version of Windows 8 or RT: If you have installed the Windows 8.1 Preview, you will not see these updates in Windows Update.

That said, Microsoft did provide updates for the Windows 8.1 Preview with this week’s set of Patch Tuesday updates. So you’ll still want to check out Windows Update. I’m seeing the following updates on my 64-bit Windows 8.1 PC:

Update improves online video playback in Windows 8.1 Preview. This update includes fixes for adaptive streaming and Digital Rights Management (DRM) playback features in Windows 8.1 Preview.

Update improves online video playback in Windows 8.1 Preview. This update includes fixes for adaptive streaming and Digital Rights Management (DRM) playback features for Internet Explorer 11 Preview in Windows 8.1 Preview.