fcp is a significantly faster alternative to the classic Unix cp(1) command.
fcp aims to handle the most common use-cases of cp with much higher performance.
fcp does not aim to completely replace cp with its myriad options.
Note: fcp is optimized for systems with an SSD. On systems with a HDD, fcp may exhibit poor performance.
Please note that fcp supports only Unix-like operating systems (e.g. Linux, macOS, etc.).
Pre-built binaries for some systems can be found under this repository's releases.
Via cargo
fcp requires Rust version 1.53.0 or newer. fcp can be installed using cargo by running the following:
cargo install fcpfcp can be installed on Arch Linux via the fcp-bin AUR.
As of NixOS 21.11 fcp is included in the stable channel. For earlier
versions, fcp is available through nixpkgs-unstable. Assuming you've
already added the nixpkgs-unstable channel, fcp can be installed by running
the following:
nix-env -iA unstable.fcpfcp can be installed on macOS via Homebrew by running the following:
brew install fcpUsage information can be found by running fcp --help, and has been reproduced below:
fcp 0.2.1
USAGE:
fcp [OPTIONS] SOURCE DESTINATION_FILE
Copy SOURCE to DESTINATION_FILE, overwriting DESTINATION_FILE if it exists
fcp [OPTIONS] SOURCE ... DESTINATION_DIRECTORY
Copy each SOURCE into DESTINATION_DIRECTORY
OPTIONS:
-h, --help
Output this usage information and exit.
-V, --version
Output version information and exit.
fcp doesn't just claim to be faster than cp, it is faster than cp. As different operating systems display
different performance characteristics, the same benchmarks were run on both macOS and Linux.
The following benchmarks were run on a 2018 MacBook Pro1 (2.9 GHz 6-Core Intel Core i9, 16 GiB RAM, SSD) with APFS as the filesystem.
The following shows the result of a benchmark which copies a directory containing 13 different 512 MB files using cp and fcp, with fcp being approximately 822x faster on average (note the units of the axes for each plot)2:
The following shows the result of a benchmark which copies the source tree of the Linux kernel using cp and fcp, with fcp being approximately 6x faster on average:
The following benchmarks were run on a bare-metal AWS EC2 instance (a1.metal, 16 CPUs, 32 GiB RAM, SSD) with XFS as the filesystem.
The following shows the result of a benchmark which copies the source tree of the Linux kernel using cp and fcp, with fcp being approximately 10x faster on average:
The following shows the result of a benchmark which copies a directory containing 13 different 512 MB files using cp and fcp, with fcp being approximately 1.4x faster on average:
fcp's high-performance can be attributed to several factors, but is primarily
the result of leveraging parallelism, distributing the work of walking
directories and copying their contents across all of your machine's cores. This
leads to a significant performance increase on systems with an SSD, as more I/O
requests are issued over the same period of time (as compared to a
single-threaded approach), resulting in a higher-average queue depth, thus
allowing higher utilization of the SSD (as a function of its maximum IOPS) and
correspondingly higher throughput.
Additionally, on macOS (and perhaps in the future on other operating systems) fcp
utilizes the system's underlying copy-on-write
capability, dramatically reducing the time needed to copy large files.
These two factors – in addition to an overall performance-conscious approach to this problem – serve
to explain fcp's significantly improved performance relative to cp.
[1] While in general you should avoid benchmarking on
laptops, fcp is a developer tool and
many developers work primarily on laptops. Also unlike with Linux where you can
rent by the second, the minimum tenancy for AWS EC2 macOS instances is 24
hours, and these benchmarks took less than an hour.
[2] The massive difference in performance in this case is due
to fcp using fclonefileat and fcopyfile under the hood.