SuperFetch(SysMain) service spikes the CPU for 1-2 minutes when a 64-bit application is running in Windows

This article provides a workaround for an issue where the system experiences CPU spike for 1-2 minutes when a 64-bit application runs in the 64-bit version of Windows.

Applies to:   Windows 7 Service Pack 1
Original KB number:   2723033


When a 64-bit application compiled with /LARGEADDRESSAWARE:NO option is running in the 64-bit versions of Windows, the system may experience CPU spike for 1-2 minutes and this goes on in-definitely. In this situation, the Task Manager shows the svchost.exe process hosting the SysMain(SuperFetch) service is consuming the CPU utilization.


Windows creates a single read-only Virtual Address Descriptor (VAD) for the address space above 2 GB while creating the process. SuperFetch while scanning the VAD tree of the running process encounters the VAD and spins with the huge VAD size, causing the CPU to spike.


To work around this issue, avoid option /LARGEADDRESSAWARE:NO while compiling the applications.


By default a 64-bit application makes use of the Extended Address Space (8 terabytes per process).