I believe the nas share is stalling, why it does this I not know, it seems to be an incompatibility between the NAS and Windows, perhaps even physical hardware related, all I know is a nas share should operate 100% the same as a local HDD. We do not have specific code for writing to a network share, it is the same simple code to write to local hdds, it is this call (a system call) which is stalling, so the issue is deep in the system, not at application level. When the network share stalls, the program will sit there doing nothing, perhaps for 10 minutes, until a time out (in the OS happens), then it will continue.

Most people do not have this slow/stalling incompatibility. Network shares are based a protocol CIFS, it is a Microsoft protocol, all linux based NASs use something like SAMBA to emulate it, well, when running audiosafe and working with millions of files, then holes in SAMBA become apparent, it is not 100%, unlike it would be if you had one Windows machine doing a network share to a 2nd Windows machine.

If you have this issue, then encoding to a local HDD, then later moving the files to the NAS might be quicker.