Strangely, those files were not the last ones in sequential order, either by name sorting or by date sorting, or even by size sorting, so apparently R-Studio relies on another criterion to determine the order in which files are extracted (and folders too : for instance a folder named “0813” was completely extracted before “0812” which is the one incomplete and containing corrupted files). So I re-extracted the last extracted folder, which was incomplete, and proceeded to compare it with the one extracted before the crash, using WinMerge : 11 files were partially or totally corrupted. Then the system crashed (Windows 7 on a NVMe SSD, I get many random crashes, with different kinds of errors, this time it was “MEMORY_MANAGEMENT”, and still couldn't figure out the root cause(s), but that's beside the point, R-Studio is not the culprit, this is just for context).

I was extracting large folders of AVI files from a video-surveillance system with R-Studio, and the rate of extraction seemed rather slow for such large files (about 100MB each, normally the reading / writing speed is significantly reduced only for small or very small files, <1MB).

Winmerge compare folders slow