How accurate is the browser-based disk speed test?

Browser-based disk speed tests provide reliable relative performance measurements, though they may show lower speeds than native software due to browser API limitations. The test is excellent for comparing drives and identifying performance issues.

What is a good disk speed for SSD vs HDD?

Modern SSDs typically achieve 200-550 MB/s read/write speeds, while NVMe SSDs can reach 1000-7000 MB/s. Traditional HDDs usually deliver 80-160 MB/s. If your results are significantly lower, check for driver issues or disk health problems.

Why is my disk speed test showing slow results?

Slow disk speeds can indicate a failing drive, outdated drivers, insufficient free space, background processes, or thermal throttling. Close unnecessary programs and ensure your disk has at least 20% free space before testing.

Does disk speed affect gaming and FPS performance?

Disk speed primarily affects game loading times and texture streaming, not FPS during gameplay. However, slow storage can cause stuttering in open-world games. An SSD significantly improves loading times compared to HDDs.

Can I test external drive speed with this tool?

Yes, you can test USB external drives, SD cards, and network drives. Results will reflect the interface speed (USB 2.0, 3.0, Thunderbolt) as well as the drive itself. USB 3.0 or higher is recommended for accurate SSD testing.

💾 DISK SPEED TESTER

Advanced storage benchmark tool. Measure sequential read/write, random I/O, IOPS, latency, and score against reference drives — all in your browser using IndexedDB.

💾

STORAGE BENCHMARK

Sequential · Random · Mixed · IOPS · Latency

READY 64 MB

ℹ️ Tests run via IndexedDB — measures your browser's storage stack. Results reflect system disk + browser overhead. Incognito mode may show lower speeds due to stricter quotas.

TEST MODES — CLICK TO TOGGLE · 12 MODES

⬇️SEQ WRITE512K BLOCKS

⬆️SEQ READ512K BLOCKS

🔀RAND WRITE4K RANDOM

🔀RAND READ4K RANDOM

NEW ⇌MIXED R/W50/50 SEQ

NEW 📚MULTI-QUEUEQD32 PARALLEL

NEW ⚡BURST WRITECACHE SPEED

NEW 🔋SUSTAINEDBYPASS CACHE

NEW ⏱️LATENCYPER-OP µs

NEW 🗜️COMPRESSCOMPRESSIBILITY

NEW 🧵THREADEDCONCURRENT IO

NEW 🏁ENDURANCESTRESS LOOP

TEST SIZE

Total data: 64 MB per test · Est. time: ~5–15s

—

SCORE

GRADE

—

LIVE THROUGHPUT

SEQ WRITE

—

SEQ READ

—

SEQ WRITE

—

SEQ READ

—

RAND WRITE

—

RAND READ

—

MIXED R/W

—

MULTI-QUEUE

—

BURST

—

SUSTAINED

—

THREADED

—

COMPRESS

—

REAL-TIME CHART

            0slive
          

—

MB/s

SEQ READ

— IOPS

—

MB/s

SEQ WRITE

— IOPS

—

MB/s

RAND READ

— IOPS

—

MB/s

RAND WRITE

— IOPS

—

AVG LATENCY

—

K IOPS

PEAK IOPS

—

—

📊 DRIVE BENCHMARK COMPARISON REFERENCE ▸

📊

REFERENCE DRIVE SPEEDS

Compare your results against common storage types and drives

SEQUENTIAL READ (MB/s)

DRIVE	TYPE	READ	BAR

SEQUENTIAL WRITE (MB/s)

DRIVE	TYPE	WRITE	BAR

YOUR RESULT vs DRIVE CLASS

—

vs HDD

—

vs SATA SSD

—

vs NVMe SSD

—

vs PCIe 4.0

—

vs RAM Disk

⚡ IOPS & LATENCY ANALYSIS DEEP DIVE ▸

⚡

I/O OPERATIONS PER SECOND

Block size impact, latency histogram, queue depth analysis

IOPS BY BLOCK SIZE

                4K8K16K32K64K128K512K1M
              

LATENCY HISTOGRAM

                <1ms2ms5ms10ms20ms50ms100ms
              

LATENCY PERCENTILES

—

P50

—

P90

—

P95

—

P99

—

MAX

📋 TEST HISTORY 0 RUNS ▸

📋

BENCHMARK HISTORY

Past test results stored locally in your browser

🗑 CLEAR

NO RUNS YET — START A BENCHMARK

⚙️ SETTINGS & ADVANCED OPTIONS 12 TABS ▸

⚙️

SETTINGS & CUSTOMIZATION

Block size, queue depth, test patterns, reporting, and more

↺ RESET

BENCHMARK OPTIONS

SEQUENTIAL WRITE TEST

SEQUENTIAL READ TEST

RANDOM WRITE TEST

RANDOM READ TEST

MIXED RW TEST (50/50)

IOPS BY BLOCK SIZE

TEST RUNS (AVG)3

WARMUP & CLEANUP

PRE-TEST CACHE WARMUP

PURGE DATA AFTER TEST

VERIFY DATA INTEGRITY

MEASURE LATENCY PERCENTILES

REAL-TIME CHART UPDATE

SOUND ON COMPLETE

PAUSE BETWEEN TESTS (ms)500ms

SEQUENTIAL BLOCK SIZE

▫64K

▪128K

■512K

⬛1M

Larger blocks → higher throughput, better for sustained transfer benchmarks (file copies, backups).

CUSTOM SEQUENTIAL BLOCK

BLOCK SIZE512 KB

RANDOM BLOCK SIZE

·4K

▫8K

▪16K

■64K

4K random I/O is the most demanding real-world workload — databases, OS paging, app loading. Smaller = harder test.

CUSTOM RANDOM BLOCK

BLOCK SIZE4 KB

QUEUE DEPTH (QD)

Queue depth = number of simultaneous outstanding I/O requests. Higher QD reveals parallelism capabilities of your storage.

1QD1

2QD2

4QD4

8QD8

16QD16

32QD32

64QD64

128QD128

⚠️ NVMe drives peak at QD32–64. SATA SSDs max at QD32. HDDs barely scale past QD1. Browser tests are limited to sequential IDB operations so QD simulates parallel chunk writes.

THREAD WORKERS

MULTI-THREADED (WEB WORKERS)

WORKER THREADS2

IO SCHEDULER

📋 FIFO — First In, First Out (default)

⚖️ CFQ — Completely Fair Queuing

⏱️ DEADLINE — Deadline Scheduler

⚡ NOOP — No Operation (SSD optimised)

WRITE FILL PATTERN

Pattern written to blocks during write tests. Affects compressibility and results on drives with hardware compression.

🔲 ALL ZEROS — Best-case for compressible drives

⬛ ALL ONES (0xFF) — Worst-case variation

🎲 PSEUDO-RANDOM — Incompressible (realistic)

↗️ SEQUENTIAL — Incrementing bytes

🌈 MIXED — Alternating blocks

I/O PATTERN

→ SEQUENTIAL ACCESS

🔀 RANDOM ACCESS

⇒ STRIDED ACCESS

⇌ MIXED (70/30 SEQ/RAND)

VERIFICATION

CRC32 CHECKSUM VERIFY

COMPARE WRITE/READ DATA

🔒 Verification adds ~15–30% overhead but confirms data integrity. Useful for checking for bit-rot or storage corruption.

GAUGE SCALE

🐢500 MB/s

🚗2 GB/s

🚀7 GB/s

⚡14 GB/s

🤖AUTO

CHART HISTORY

HISTORY POINTS120

THEME

DARK MODE

RAINBOW BORDER ANIMATIONS

SHOW GAUGE NEEDLE

ANIMATE STAT NUMBERS

CHART DISPLAY

FILL AREA UNDER CURVE

SHOW GRID LINES

SHOW ALL CHANNELS

SMOOTH LINE INTERPOLATION

UNITS

📊MB/s

📈GB/s

📡Mbit/s

CHART STYLE

📈LINE

📊BAR

🌊AREA

EXPORT FORMAT

📄TXT

📊CSV

🗃️JSON

🌐HTML

REPORT CONTENT

INCLUDE SEQ READ/WRITE

INCLUDE RANDOM READ/WRITE

INCLUDE IOPS DATA

INCLUDE LATENCY PERCENTILES

INCLUDE SYSTEM INFO

INCLUDE CHART IMAGE

REPORT PREVIEW

Run a benchmark to see a report preview here.

AUTO-EXPORT

AUTO-EXPORT AFTER BENCHMARK

SAVE TO HISTORY AUTOMATICALLY

BROWSER STORAGE INFO

—

USED

—

QUOTA

—% used

STORAGE API

USE INDEXEDDB (PERSISTENT)

USE CACHE API (VOLATILE)

USE OPFS (ORIGIN PRIVATE FS)

DATA MANAGEMENT

TEMP FILE SIZE

Benchmark creates temporary blobs in IndexedDB. Size = test data size × 2 (write + read). Auto-purged after each test if "Purge After Test" is enabled.

BUILT-IN TEST PROFILES

One-click profiles pre-configure test modes, sizes, and block sizes for specific drive types and use cases.

⚖️

BALANCED

SEQ+RAND · 64MB · Best for general purpose

🚀

NVME STRESS

All modes · 256MB · Multi-queue QD32 · Full suite

💿

SATA SSD

SEQ+RAND · 128MB · QD1 · 512K seq block

🖴

HDD / SPINDLE

SEQ only · 32MB · 1M blocks · Skip random

🔌

USB DRIVE

SEQ+RAND · 16MB · Burst test · Short run

🎮

GAMING

RAND READ focus · 64MB · 4K blocks · Latency test

🖥️

WORKSTATION

Mixed R/W + Threaded · 128MB · Endurance included

⚡

QUICK CHECK

SEQ only · 4MB · 1 run · Under 5 seconds

SAVE CUSTOM PROFILE

PROFILE NAME

DESCRIPTION (OPTIONAL)

SAVED PROFILES

NO SAVED PROFILES YET

PROFILE AUTO-APPLY

AUTO-APPLY LAST USED PROFILE

REMEMBER PROFILE ON RELOAD

SPEED THRESHOLD ALERTS

Get notified when results exceed or fall below target thresholds. Useful for detecting drive degradation or verifying upgrade performance.

ENABLE THRESHOLD ALERTS

DESKTOP NOTIFICATION (PUSH)

PLAY ALERT SOUND

HIGHLIGHT FAILING STAT CARDS

SEQ READ THRESHOLD

MIN EXPECTED200 MB/s

SEQ WRITE THRESHOLD

MIN EXPECTED150 MB/s

RAND READ THRESHOLD

MIN EXPECTED20 MB/s

RAND WRITE THRESHOLD

MIN EXPECTED15 MB/s

LATENCY THRESHOLD

MAX ACCEPTABLE (ms)20 ms

ALERT CONDITIONS

📉 ALERT WHEN BELOW THRESHOLD

📈 ALERT WHEN ABOVE THRESHOLD

↕️ ALERT ON BOTH CONDITIONS

ALERT HISTORY

NO ALERTS TRIGGERED YET

DEGRADATION DETECTION

COMPARE TO LAST RUN

COMPARE TO BEST EVER

DEGRADATION % TO ALERT15%

⚠️ Desktop notifications require browser permission. Click the toggle to request access. Alerts always show as on-screen toasts regardless of permission status.

COLOUR SCHEME

CYAN (DEFAULT)

NEON GREEN

GOLD

PURPLE

ORANGE

RED/PINK

CUSTOM ACCENT

#00e5ff

BACKGROUND STYLE

🌌 RADIAL GRADIENT (DEFAULT)

⬛ SOLID DARK

🕸️ MESH GRID

📺 SUBTLE NOISE

🪟 TRANSPARENT (MINIMAL)

GAUGE STYLE

🌈 GRADIENT ARC (DEFAULT)

💠 SOLID ACCENT

📊 SEGMENTED ZONES

➰ MINIMAL LINE

UI DENSITY

▪COMPACT

■NORMAL

⬛SPACIOUS

ANIMATIONS

RAINBOW BORDER ANIMATIONS

STAT NUMBER COUNT-UP

GAUGE NEEDLE ANIMATION

BAR FILL TRANSITIONS

REDUCE MOTION (ACCESSIBILITY)

ANIMATION SPEED1.0×

FONT SIZE

AXS

ASM

AMD

ALG

MIXED R/W CONFIGURATION

READ RATIO50% R / 50% W

INTERLEAVE OPS (vs BATCHED)

MULTI-QUEUE CONFIGURATION

DEFAULT QUEUE DEPTHQD 32

MEASURE PER-WAVE LATENCY

BURST WRITE CONFIGURATION

BURST OPERATION COUNT512 OPS

BURST BLOCK SIZE4 KB

SUSTAINED WRITE CONFIGURATION

SUSTAINED DATA SIZE64 MB

SHOW CACHE-EXHAUSTION POINT

LATENCY TEST CONFIGURATION

SAMPLE COUNT200

MEASURE READ LATENCY

MEASURE WRITE LATENCY

THREADED READ CONFIGURATION

CONCURRENT THREADS4

STAGGER THREAD START (10ms)

ENDURANCE CONFIGURATION

CYCLE COUNT5

DATA PER CYCLE16 MB

SHOW PER-CYCLE BREAKDOWN

ALERT ON SPEED DROP > 20%

💡 More cycles = better endurance picture, but longer runtime. Use 5 cycles for quick checks, 10+ for rigorous SSD degradation testing.

DISKSPEED

ADVANCED STORAGE BENCHMARK TOOL

v1.0.0 12 SETTINGS TABS INDEXEDDB LOCAL ONLY

HOW IT WORKS

DiskSpeed uses the browser's IndexedDB API to write and read large binary blobs, measuring throughput via performance.now(). This measures the full stack: JavaScript engine → browser storage layer → OS filesystem → physical disk.

Results are typically 10–40% lower than native tools (CrystalDiskMark, fio) due to browser overhead, but trends and relative comparisons are accurate and meaningful.

KEYBOARD SHORTCUTS

Space / Enter	Start/stop benchmark
R	Reset all results
E	Export results
H	Show/hide history
+ / -	Increase/decrease test size
1–4	Select test size (16/64/256/1024)
Esc	Stop running benchmark

PRIVACY

🔒 100% local processing. All data stays in your browser. No metrics, results, or storage data is ever sent to any server.

📖 UNDERSTANDING YOUR RESULTS GUIDE ▸

⬇️⬆️ SEQUENTIAL R/W

Measures sustained throughput with large contiguous blocks. Relevant for copying large files, streaming 4K video, backups. HDDs: 80–160 MB/s. SATA SSDs: 400–550 MB/s. NVMe: 2–7 GB/s.

🔀 RANDOM 4K R/W

The most important real-world metric. Databases, OS boot, app launch, file indexing. HDDs: 0.5–2 MB/s. SATA SSDs: 20–100 MB/s. NVMe: 200–800 MB/s.

⚡ IOPS

I/O Operations Per Second. HDDs are limited to ~80–200 IOPS by physical seek time. SATA SSDs: 10K–100K. NVMe: 100K–1M+ IOPS.

⏱️ LATENCY

Time to complete a single I/O request. HDDs: 5–15ms (mechanical seek). SSDs: 0.05–0.2ms. Crucial for interactive workloads and gaming.

🌐 BROWSER vs NATIVE

Browser benchmarks run through JS → V8 → OS → Disk. Expect ~10–40% lower than CrystalDiskMark. Useful for relative comparison and trend analysis.

💡 TIPS FOR ACCURACY

Close other browser tabs. Disable extensions. Use a regular window (not incognito). Run 3+ times and average. Larger test sizes give more stable results.