Speed up copies with robocopy /MT multithreading
The forgotten robocopy switch that parallelizes file copies — a big win when copying many small files.
01Command
$ robocopy C:\Source D:\Dest /E /MT:1602What it does
/MT spawns n threads that process different files simultaneously, which dramatically improves throughput on trees with many small files where a single-threaded copy spends most time on per-file overhead. It accepts 1–128 threads; more is not always faster since disk seek contention can dominate. /MT can't be combined with /IPG (inter-packet gap) or /EFSRAW, and its progress logging interleaves threads.
03Risk
04Undo
✓No undo needed — this command does not change persistent state.
05Sources
- robocopy | Microsoft LearnEvidence: Microsoft documents /MT[:n] to create multi-threaded copies with n threads (1-128, default 8) and notes it is incompatible with /IPG and /EFSRAW.
- ROBOCOPY - Windows CMDEvidence: SS64 describes /MT:n as multi-threaded copying with a range of 1-128 threads, default 8, improving throughput on many small files.
Last verified: 2026-09-17 · Category: Files & Folders
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