USB Speed Tester

A real storage throughput, IOPS, latency, and sustained-write cache-dropoff benchmark utility for USB flash drives, SD/microSD cards, external SSDs, and Linux filesystems.
A lightweight Linux alternative to FlashDriveSpeed and USB Flash Benchmark for testing multi-block transfer speeds and exposing fake speed ratings or SLC cache cliffs.

Key features:
- Live filesystem and hardware inspector reading /proc/mounts, os.statvfs, /sys/block/* device attributes, and /sys/bus/usb/devices link speeds (480 / 5000 / 10000 Mbps).
- Genuine Sequential and Random Read/Write benchmarks across 4 KiB, 64 KiB, 256 KiB, 1 MiB, and 4 MiB block sizes using os.fsync and POSIXFADVDONTNEED page-cache hints.
- Visual multi-block Read vs Write MB/s bar chart with IOPS and per-operation millisecond latency table.
- Sustained Write Throughput curve plotting MB/s across continuous written megabytes to reveal thermal throttling and flash cache dropoffs, with CSV and JSON report export.

Disclaimer: This project is an independent open-source tool and is not affiliated with, sponsored by, or endorsed by FlashDriveSpeed or its respective authors.