WizTree is famously almost 50x faster than WinDirStat (on normal Windows NTFS drives) by reading the Master File Table (MFT) instead of walking the tree to measure each file.
WizTree isn't open-source like WinDirStat but "free as in beer" with optional donations.
WizTree isn't open-source like WinDirStat but "free as in beer" with optional donations.
There's also a fork of WinDirStat patched to read the MFT but I don't know anyone who's tried it: https://github.com/ariccio/altWinDirStat