# Diskio: Disk & SSD Speed Test — Read, write & external drives

> Accurate disk speed testing for internal and external storage devices on iOS. (iPhone/iPad app by Sergii Khliustin.)

- Source: https://appshunter.io/ios/app/diskio-disk-and-ssd-speed-test/id6467768299 (this page in markdown: same URL + `.md`)
- Developer: [Sergii Khliustin](https://appshunter.io/developer/1598605990)
- Category: Utilities, Productivity
- Price: $5.99
- Rating: 3.90/5 from 17 App Store ratings · 9 written reviews indexed
- Age rating: 4+
- Requires: iOS 16.0 · 10 MB
- Languages: American English, Japanese, Chinese (Simplified, China), European Spanish, Ukrainian
- Released: 2023-10-02
- Data updated: 2026-09-29
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/diskio-disk-and-ssd-speed-test/id6467768299/reviews.md

## What is Diskio?

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
Diskio 3.0 reworks the speed calculation and test-file sizing. 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 redesigned interface supports light and dark appearances, larger text and Reduce Motion.

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. Measurements in version 3.0 may differ from earlier versions because the method has changed.

## Key features

- Precise disk speed testing
- Tests internal and external storage
- Customizable test parameters
- Simple three-step process
- Universally compatible with iOS devices
- Identifies performance bottlenecks

## Recent user reviews (9 of 9)

All indexed reviews: https://appshunter.io/ios/app/diskio-disk-and-ssd-speed-test/id6467768299/reviews.md

### 5/5 — Wolf

*2026-08-02*

Super!

### 1/5 — 垃圾软件，每次结果都不准

*2026-03-19*

和其他软件差天上去去啦

### 1/5 — 每次测试数值差很多，这是不是不准啊

*2025-12-16*

每次测试数值差很多，这是不是不准啊

### 5/5 — Чудова апка

*2025-09-18*

Натхнення вам)

### 3/5 — Needs Dark mode

*2024-12-19*

Other than that, needs dark mode as my phone is on it but the app opens it in light.

**Developer response:** Hello, thanks for your review!
In 2.0.0 we added light and dark modes support. 
Enjoy!

### 1/5 — Problem mit Disk

*2024-05-03*

Mit externen Speichermedien wie SD Karten verweigert die App den Dienst. Es wird direkt nach dem Start des Tests immer ein Problem mit der Disk gemeldet und der Vorgang bricht ab. Unbrauchbar.

**Developer response:** Hello, thanks for your review!
Could you please check if you have enough free space on your SD card? Also check that it actually works with iOS. Try to create a file via Files app.

### 5/5 — Fantastic disk speed test app

*2024-01-11*

Once you open the app you need to go to the bottom and swipe up to get to the settings.

Choose your location = SSD, disk etc.
Test size choice = 1,2,3,4,5 GB
Chunck size choice =1,2,4,8,,16 MB
Run test and the READ & WRITE scores will show.  
*BONUS*  You get a message with your score. 
If your external drive is very fast, you have to read the sheer awesome message it displays in the end. Bravo Diskio programer(s)

### 3/5 — Not Sure I Can Trust Accuracy

*2023-10-26*

I’m trying to use Diskio to compare external storage access speeds on my 3rd Gen iPad Pro to my new iPhone 15 Pro.  I’m also using Blackmagic Disk Speed Test on my Mac Mini to compare Diskio results. 

Blackmagic is measuring about 680MB/s both read and write on an 800MB/s Sandisk SSD.  Diskio is reporting 7808 MB/s write and 958MB/s read on my iPhone and 3553 MB/s write with 625MB/s read on the iPad Pro.  Seems write speed is questionable AND the units probably should be Mb/s!

Ease of use is great. With the new USB C port on iPhones, more of you will be trying to measure speeds. This possibly could be the right tool if it were truly accurate.

**Developer response:** Hello, thanks for your review!
In 2.0.0, we fully reimplemented the algorithm, so you can now trust the accuracy of the results.
Enjoy!

### 5/5 — Danke für diese App!

*2023-10-03*

Eine wirklich brauchbare App! Habe lange danach gesucht und endlich gefunden! Dankeschön!

## Frequently asked questions about Diskio

### What is Diskio?

Diskio is a utility app designed to perform precise speed tests on all your storage devices, including internal iPhone storage and external drives connected via USB-C or Lightning. It helps you understand your storage's true performance.

### How does Diskio test disk speed?

Diskio uses advanced algorithms to deliver accurate speed tests. You can select your storage location, choose test parameters like file size and chunk size, and then get comprehensive results.

### What devices does Diskio support?

Diskio is universally compatible with all iOS devices, including iPhones and iPods, and works with external storage solutions like USB drives and SD cards.

### How much does Diskio cost?

Diskio is a paid application, priced at $5.99. This one-time purchase grants you access to its full suite of disk speed testing features.

### How often is Diskio updated?

Diskio was last updated on June 3, 2025, with version 2.1.0. It is regularly updated to ensure compatibility with the latest iOS versions and to enhance its features.

### What is the age rating for Diskio?

Diskio has an age rating of 4+, making it suitable for a wide range of users. This indicates it contains no mature content.

### Does Diskio have ads?

Yes, Diskio contains advertisements. As a paid application, these ads are part of the user experience.

### What are the benefits of using Diskio?

Diskio helps you identify performance bottlenecks, make informed storage purchase decisions, verify advertised speeds, and monitor drive health over time, ensuring you get the most out of your storage.

## Version history (last 5 releases)

### 3.0.0 — 2026-09-24

Diskio 3.0 brings a redesigned interface and a reworked measurement method.

• Corrected speed calculations and test-file sizes. Write measurements now include final filesystem synchronization.
• Choose 1, 3 or 6 runs. View median speeds, min–max values and every individual result.
• Choose 6 runs to check result stability using adapted SNIA numerical criteria. This is not a full SNIA-compliant benchmark.
• Share the full report with test settings and stability results.
• Clearer progress, low-space warnings, improved cancellation and support for larger text and Reduce Motion.
• A new icon and updated translations in all five languages.

Results may differ from earlier versions because the measurement method has changed.

### 2.1.0 — 2025-06-03

Welcome to Diskio 2.0! We've completely reimagined your favorite disk speed testing app!
- Enhanced Testing Engine - Our improved algorithm delivers even more precise results, giving you the most accurate storage performance metrics available.
- ¡Hola! こんにちは! 你好! Now fully localized in Spanish, Japanese, and Chinese, bringing professional-grade disk testing to more users worldwide.
- Light Theme Support - Experience Diskio in a fresh new look! Perfect for daytime use with a clean, modern interface.
- Performance Optimizations - Faster, smoother testing process with improved reliability for all your connected storage devices.
Upgrade today and discover what your drives are truly capable of!

### 2.0.1 — 2025-03-23

Fixed crash on start on some devices

Welcome to Diskio 2.0! We've completely reimagined your favorite disk speed testing app!
- Enhanced Testing Engine - Our improved algorithm delivers even more precise results, giving you the most accurate storage performance metrics available.
- ¡Hola! こんにちは! Now fully localized in Spanish and Japanese, bringing professional-grade disk testing to more users worldwide.
- Light Theme Support - Experience Diskio in a fresh new look! Perfect for daytime use with a clean, modern interface.
- Performance Optimizations - Faster, smoother testing process with improved reliability for all your connected storage devices.
Upgrade today and discover what your drives are truly capable of!

### 2.0.0 — 2025-03-22

Welcome to Diskio 2.0! We've completely reimagined your favorite disk speed testing app!
- Enhanced Testing Engine - Our improved algorithm delivers even more precise results, giving you the most accurate storage performance metrics available.
- ¡Hola! こんにちは! Now fully localized in Spanish and Japanese, bringing professional-grade disk testing to more users worldwide.
- Light Theme Support - Experience Diskio in a fresh new look! Perfect for daytime use with a clean, modern interface.
- Performance Optimizations - Faster, smoother testing process with improved reliability for all your connected storage devices.
Upgrade today and discover what your drives are truly capable of!

### 1.0.5 — 2023-10-25

- Improved stability

## Apps similar to Diskio

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| [SSD Performance Test](https://appshunter.io/ios/app/ssd-performance-test/id6740139555) | — | Free | Utilities |
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## More apps by Sergii Khliustin

- [Buildio - Bitrise client](https://appshunter.io/ios/app/buildio-bitrise-client/id1598605988)
- [NoPapel - Receipts splitting](https://appshunter.io/ios/app/nopapel-receipts-splitting/id6743413760)

All apps by Sergii Khliustin: https://appshunter.io/developer/1598605990

## Related topics

[rec disk speed test](https://appshunter.io/ios/topics/rec-disk-speed-test) · [disk speed test](https://appshunter.io/ios/topics/disk-speed-test) · [super disk speed test 2.0](https://appshunter.io/ios/topics/super-disk-speed-test-2-0) · [disk speed](https://appshunter.io/ios/topics/disk-speed)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-29.*