Resolving slow build issues in Embedded Studio on Windows

When building large projects you may experience a slowdown in build time and high CPU load. The high CPU load is normal as the default for Embedded Studio is to launch parallel builds where possible to build faster.

However, the build process may be slowed down. This can be caused by the Windows Defender antimalware and antivirus checks.

Windows Defender runs in the background and check each file that is created and written. During a build, many, many files are written by the compilation process (assembly language intermediate files and object files, for instance), and the Windows antimalware service checks each one of them. If you open the Task Manager what you see is that up to 50% of available CPU cycles are taken by the antimalware checks along with a large memory requirement:

Excluding volatile work folders from Windows Defender

It is possible to exclude your work directories from antimalware checks and recover the CPU cycles that the antimalware check consumes.

On Windows 10

• Run the Windows Security app using the Search box in the task bar.
• Click Virus & threat protection.
• Under Virus & threat protection settings click Manage settings.
• Under Exclusions click Add or remove exclusions.
• Click Add an exclusion.
• Select Folder and add the root folder of your working area.

On Windows 7

• Click the Start button and run Microsoft Security Essentials.
• Select the Settings tab.
• Click Excluded files and locations.
• Click Browse and select the root folder of your working area.
• Click Add.
• Click Save changes.
• Allow changes to be saved, if prompted.

Resolving issues with other antimalware tools

When you are using another antimalware or antivirus tool, you might experience similar issues.

These can be caused by the checks described above. Another reason in some cases is that the antimalware tool slows down the build tools itself.

Embedded Studio and all included executables are non-malicious and digitally signed. This should stop the tools from checking them.

However, some antivirus software might ignore this and continuously check the build tools on each invocation, which might slow down the tools itself or, as Windows Defender, require hughe CPU usage.

In that case, contact the antimalware software vendor for how to whitelist Embedded Studio or exclude it and the work directories from malware checks.