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To download Blackmagic Disk Speed Test from the Mac App Store, you need a Mac with OS X 10.6.6 or later. Learn More.

Blackmagic Disk Speed Test

By Blackmagic Design Inc

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Disk Speed Test is an easy to use tool to quickly measure and certify your disk performance for working with high quality video! Simply click the start button and Disk Speed Test will write test your disk using large blocks of data, and then display the result. Disk Speed Test will continue to test writes and reads from your disk so you can evaluate both performance and readability over time.

What's New in Version 2.2.2

Improved compatibility with Mac OS X 10.10 Yosemite.


Screenshot 1

Customer Reviews

For all those having the “Read Only” issue...

This excellent product works precisely as advertised. If, like BBurr55, you think it doesn’t function because you get a message saying your drive is "read only” and you need to pick a drive with Read/Write privileges, you might be forgiven for thinking that’s nonsense because, "I’ve been reading and writing to them both before and after the test.” You might be forgiven for thinking that, but you’d still be wrong. Mac example: Though you can read and write to your external drives, that’s because the computer knows you as Administrator (or “system"). Open the Finder and go to the external drive you want to test. If you have right-click enabled on your mouse, do that or go FIle>Get Info or Command+I . When the Info window opens you’ll see at the bottom that under Sharing & Permissions “system" and “wheel" are set to Read & Write, but “everyone" is set to Read only. This is by default to keep hackers and malware from writing to your drive. It sees the App, Blackmagic Disk Speed Test, as “everyone” To run the test click the lock in the lower right-hand corner of the Info Window and enter your password to unlock. Change “everyone" to Read & Write and then close the window. You can now run the speed test. You should change the settings back when finished for security.

Great App, but judging by the complaints you might want to warn about this in advance. Thanks!

Simple UI That is Not Intuitive

This is an example of simplicity that is not intuitive. There is no information on how to use the tool, just two speed dials, a large “Start” button and a settings button in the center, and a table of data at the bottom. There is no explanation on what “stress” size to choose, and once the tool starts, it never stops until you click on the “Start” button again. I had to read the documentation to learn that is how one stops the tool. There is no indicator or information in the UI to tell you how many times you should let the reads and writes complete, or a progress indicator. The UI for selecting the drive to test looks like Finder, so at first I thought I clicked on Finder accidentally, rather an intuitive UI (e.g., radio button) to select the available drives. The data table has no explanation in the UI.

Also, you cannot easily test the internal drive where the OS resides, since after I read NothingToGain’s review, I learned you have to, via OS X, temporarily provide everyone with write permission to the drive in order to do the test. Again, this information should be provided in the UI.

As for the data, I have not verified it, but I will give it the benefit of the doubt given others on the Internet have indicated that it works.

Make sure to select a place in the directory structure you can write to...

For all those having “Read-only” problems, all you should need to do is to navigate down to a point in the directory structure where you know that you have full read-write privileges. So, if you want to try testing the OS boot drive, navigate down to your home directory, and you should be done. If there are other volumes you want to test, you need to make sure you do so in a place in the respective directory structure where you have full read/write privileges.

That said, this tool only seems to test sequential I/O, not random I/O. And it gave me some wildly varying numbers (like, by a factor of two) on my internal SSD, as well as other devices I tried it on. Finally, I also have iStat Menus and LittleSnitch Network Monitor installed, and while BlackMagic was doing the disk testing, I didn’t see a single blip in the disk I/O or network I/O meters, which tells me that something really strange is going on.

I’m going to try some other disk benchmarking tools that will hopefully include random I/O as well as sequential I/O, and see how that works out.

Blackmagic Disk Speed Test
View in Mac App Store
  • Free
  • Category: Video
  • Updated:
  • Version: 2.2.2
  • Size: 23.0 MB
  • Language: English
  • Seller:

Compatibility: OS X 10.6.6 or later

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