I found that by turning off the Microsoft Security Essentials (malware security monitor) when moving files from one archive to another, speeds up Teracopy about 5x to 10x in file transfer speed. A HUGE speed increase. Teracopy alone gives about another 3x improvement over explorer. So Security Essentials Real-time file checking is the main bottleneck, and it can be turned off temporarily during copying files from archive to archive. Since the archives were already checked for malware, this approach is safe for moving large files in large archives. Once the archives are copied, then I turn it back on. It seems to me this could be at least a suggestion to the user before making a large copy (100G+) or possibly done automatically by Teracopy, then turned back on after the copy. It is a sweet trick and it works!
Customer support service by UserEcho