The VSE on-demand scanner (ODS) architecture was improved in VSE 8.8 to be multi-threaded, so that ODS could complete in much shorter times.

To facilitate scanning, one pool of threads reads from the hard drive to build a list of file objects to scan. Another pool of threads removes items from that list as the file object is scanned.

Unfortunately, the list of files to scan tends to be populated faster than the scanning threads can remove items from the list. So, depending on the number of files to be scanned, the list can grow in memory to be large. There is no limit to the size of the list, so it can grow to multiple gigabytes in size. The following three things influence the size:

• The number of files on disk
• The speed of scanning to reduce the list
• The amount of data needed to store the full path and file name of each file

Restricting the ODS performance threshold to Very low thread priority limits the number of threads used by the ODS, but it might be insufficient to avoid this issue.