Jazz Disk Bench Pro vs Diskio

Jazz Disk Bench is a pro-grade storage performance measurement tool designed for SSDs, SD cards, and internal/external storage. Get accurate data on your device's throughput with industry-standard testing methods. Key Features: * Sequential Speed Test: Measure peak performance for copying large files (movies, games, etc.). * 4K Random IOPS: Evaluate system responsiveness. Low random performance is often the root cause of device lag. * Pro Stress Test: Push your storage to the limit with 2GB–100GB tests to check stability and "real" NAND speed after cache exhaustion. * External Storage Support: Fully compatible with USB drives and SD cards via custom folder selection. Benchmark Details: * Sequential Test: Reads/writes 16MB blocks sequentially. Perfect for testing raw transfer speeds. * Random Test (4K): Reads/writes 4KB blocks at random locations. This reflects how fast your OS launches apps and handles small files. * Stress Test: Sequentially writes massive data (up to 100GB). Ideal for pro users to test SLC cache size and sustained NAND write performance. Note: For external storage tests, ensure a stable connection and write permissions.

How fast is your storage? Measure sequential read and write speeds on your iPhone or a compatible external drive. Go beyond one number with repeat runs and a detailed report. SEE THE WHOLE RESULT Choose 1, 3 or 6 runs. With 3 or 6 runs, see median read and write speeds, minimum and maximum values, and the result of every run. CHECK CONSISTENCY Choose 6 runs to assess read and write stability separately over the last five. See whether results are stable or vary, with the criteria explained in the app. TEST YOUR SETUP Use your iPhone's internal storage or select a compatible, writable external drive through Files. Choose a test file from 1 to 5 GiB and a block size of 1, 2, 4, 8 or 16 MiB. The defaults are 6 runs, a 1 GiB file and a 2 MiB block. UNDERSTAND THE MEASUREMENT Speeds are shown in MB/s, and write timing includes final filesystem synchronization. Follow each write and read phase as the test runs. SHARE THE DETAILS Send a result card with the full report, test settings and, after 6 runs, the stability assessment. The interface supports light and dark appearances, larger text and Reduce Motion. ADAPTS TO YOUR DISPLAY On iPhone Duo, an expanded layout gives controls and results their own space. Your report stays available as the layout changes, and narrow windows use a compact view. GET STARTED 1. Select your storage and test settings. 2. Start the test and keep Diskio open. 3. Review the report or share your results. A test needs enough free space for a temporary file. External storage must be accessible and writable through Files. Results depend on the device, storage, connection, free space and test settings. The stability assessment adapts numerical criteria from SNIA SSS PTS. It is not a full SNIA-compliant benchmark, a drive-health check or a sustained-performance rating. Results from version 3.0 onward may differ from older versions because the measurement method was revised.