Microsoft confirms slow start-up persistent memory glitch in Windows

Persistent memory is non-volatile RAM that retains its content through power cycles

Microsoft has acknowledged a new bug affecting several versions of Windows causing slow startups on devices configured to use persistent memory (PMem).

"After you configure a Windows-based computer to use large amounts of memory, including persistent memory, the computer takes longer than expected to start up," Microsoft said in a support document.

"Additionally, increased CPU usage occurs for a short time after startup. Increased CPU usage occurs when an application frees and reallocates large ranges of memory in rapid succession," it added.

PMem is a type of memory technology that offers a combination of affordable large memory capacity and persistence. PMem is non-volatile RAM that can retain its content through power cycles. Even if the power goes down due to an unexpected power loss, system crash or user initiated shutdown, the contents of PMem remain intact.

Because of this special feature, PMem can be used as storage and therefore sometimes referred to as the 'storage-class memory'.

This technology is used for both Windows Servers as well as Windows clients.

According to Microsoft, when a system is configured to use huge amounts of memory, including PMem, delays during restarts and during memory freeing at runtime become inevitable as all physical memory must be cleared by the system before it can be used again.

According to Microsoft, the bug is triggered only when the PMem is used in memory mode. System startup time is not affected when the PMem feature is set as a storage device.

Fortunately, Windows 10 Home users are not impacted by the issue since Home edition doesn't use the PMem feature.

Only the following Windows editions are impacted by the issue:

The company said that future Windows releases will address the issue by providing additional optimisations in start-up path.