Blackmagic Disk Speed Test

A few easy UI tweaks would make this a five star app: 1) The name of the drive to be tested doesn't appear anywhere on the window. It should. 2) The Start/Stop button is only labeled "Start." When running, the label should change to "Stop." 3) There is no way to set the number of write/read loop iterations for a test. Control is entirely manual. 4) There is no loop count, so a user needs to carefully watch/monitor the test to know how many times it has been performed. 5) A log of the write/read speeds, for each loop iteration, would be nice.

Blackmagic has been updated to adequately report the speed of SSD devices. When Blackmagic tries to read the Startup Disk, you get the message that the device is not writeable, hence you cannot rate the the transfer rates of the drive. I found a workaround that will report the rates of the Startup Disk. Its quite simple. Create a disk image (.dmg) using the disk utility specifying file->new image->blank image. Make it big enough for Blackmagic to work with (7+ GB) and name it what you will. Mount the volume (if it is not already mounted). In Blackmagic select the disk image mounted. Since the “volume” is on your Startup Disk, you will see how fast it drive is. On my 2016 MacBook Pro, I am seeing speeds like 1,000+ MB/s write, and 1100+ MB/S read. I have tried this on my older mackbooks with SSD and they do scale down as the device is older. On an older MacBook Pro the rates I see are 500 MB/S both read and write, as you would expect. I have run Blackmagic on USB 2, thumb drives, USB 3, and USB C devices to see if I’m getting my money’s worth. You can easily detect when a device is performing subpar and, and with the spinning disk, you can see is transfer speeds deteriorates over time.

It works on local drives and network drives, which is great. With my M2's drive testing at >2GB/s a 5GB file seems too small to really test accurately. Though the focus of this app isn't for accuracy but rather a quick tester for video files, so I guess thats okay. One odd feature is that once I start the Speed test, it won't stop until I interfere- it just keeps running the test over and over. This wouldn't be so confusing except the button still says "start", so you need to click start to stop it. Another slight annoyance is every time you save a screenshot, it doesn't remember where you last were and you need to navigate to the folder you want every time.

Disk Speed Test is a very useful product and one cannot complain about the price point. However, a few enhancements would make this program truly wonderful. Ability to Specify Number of Runs Instead of just running forever, it would be nice to be able to specify that Disk Speed Test is to run some user specified number of times. Ability to specify the pause period between runs At the default values, it is hard to stop the program after it has totally finished one test, and before it has started another. It would be nice to be able to specify a pause between runs. Log File It would be nice if Disk Speed Test had an option to save a log file with the test results for each run. Something that one could import into Excel or some other spreadsheet would be idea. Command Line Run The ability to run Disk Speed Test from the command line would allow for automation. And also for remote collection of such data by admins, who could use this feature with ARD or other secure command line login.

My desktop system has a lot of drives, and this is invaluable for learning how well each of them perform. It would be a lot more helpful if the display actually listed which drive was being tested, and not just the final directory. It would be amazing if I could just give it a list of drives (internal, external and network), have it run and print out a simple text report on the performance of each one. The question often isn't whether one particular drive is fast enough, but which drive would be best.

The lastest version of macOS 12.2.1, broke this app. Now when you run a test it will glitch and the test reading will drop after the test is either paused or when it moves to re-start another test. it the 10 years i used this app this has never happend. (2) we really could use a feature to choose what kind of test we want to have as in how many runs the app makes and say the menu bar. where tou can choose to have it (run once, or run unlimted times) this is so needed!!!

I think the choice to let the app run tests continuously, and never complete is a weird choice. Maybe it's because I'm used to the Ookla speed test and CrystalDiskMark. Maybe I haven't figured out the workflow advantage of having it run indefinitely. Either way, the fact that I find it a little odd has nothing else to do with the functionality of the app. It seems very good. I am running it on OS 13.1 on

i wish it had a button in the UI to cancel current test. i know i can simply quit application but doing that on SD cards always makes me nervous. I know about all the pertient data i need from the first couple reads/writes on an SD card, dont need the full 10min + run of tests. But an awesome tool nonetheless. Installed and ran immediately on Sierra 12.6, but doesnt open when you click to launch from the Mac store, so close the store and open from applications drawer.

It's a free app... hard to be down on something that costs nothing. Right? I've been using black magic for what seems like forver, and it's a useful tool to benchmark the various drives I have in orbit at a given time for various use e.g. too slow for anything but time machine backup or fast enough for 4k video editing, etc. Could the UI be improved a little? Sure, but it's a 5 star app for what it does.

As other reviewers have mentioned, the user interface has some serious but easily fixed problems that make the program difficult to use at first. To fix these, 1. Have a separate Stop button or change the text on the Start button to Stop when the test is running. 2. Display the name of the drive being tested. 3. When saving a screenshot of the results, don't just use the current status, use the results of a full test. 4. The markings on the "tachometers" (like the red zone) are irrelevant and therefore confusing. 5. The "read-only" error message should say that sometimes you must choose a subfolder to make the test work. 6. Selecting the test drive should not be in the Setup.

All I wanted to press start and have it give me a read and write speed I could compare to other flash drives. Instead it begins this long series of reads and writes over and over again, with no progress bar indicating when, if ever, it will finish, and populates a table of video formats your drive will work with. As someone else mentioned, the state machine on the ONE control - the "Start/Stop" button - is broken. As an iOS Developer, I cannot concieve of how this has spent at least a year unfixed.

Agree with "Brandyhawk." The UI needs some serious improvements. It doesn't show which drive is being tested (or make it easy to actually select a drive), it doesn't show percentage complete (a first for a speed test app I've used!!) even though a progress meter is available but kinda hard to interpret, etc. Otherwise a useful app for testing new external drives, and works on Apple Silicon.

I use this often and appreciate it. The update (3.1) seems to provide much more stable speed readings than the 2.x version I've been using (where the guage is all over the map). One issue I have is that it seems to have issues with NTFS formatted drives. I'm using Paragon's NTFS for Mac, and BMDST writes to it well (430 to my SSD) but on the read test it often (though not always) fails with "Error reading the test file". Aside from this niche case it's an awesome tool.

seems like a simple enough application except for a couple of usability points under the voiceover screen reader: 1. the primary button on the main pane is unlabeled as are the check boxes. 2. choosing a disk causes the application to crash out and not open a crash dialog 3. also, the app appears to alternate between busy and non-busy states when any of the check boxes are accessed. So, that is why I rated it only a 3 (it is usable, but not entirely by us blind users. Please check the Apple Accessibility API (as published on their developer site) to make the appropriate changes.

this app hgas worked great for me over many years, ever since I first installed a SSD in my old 2008 MBP. Those reviews that say it can’t test read/write speeds on their startup disk - it sure seems to do a bang-up job for me. Also, those reviews that want to cancel the test? My version runs until I click the big red button to stop it.

I think this is really good despite the negative star rating overall. The only thing I don't like about it is that it keeps running speed tests until you hit stop and has all the advanced stuff at the bottom without being able to convert to basic but overall, I think this is the best alternative to CrystalDiskMark for Windows.

Works great across all my (different types of) drives. Would love to see display of which drive is being tested! Would be good to have hints that you need a writeable drive/folder. Only indication is "open" button is enabled or not. Please can we get an update? Would like to specify how many runs, as well ;-)

If you think you don't like this tool, read more reviews. There are a lot of good tips in these reviews. For example: if it seems to not want to test a volume you know you can read/write to, make a disk image at least 10 GB (read/write) on the volume you want to test. Mount it, and aim BMST at that. Remember to delete the dmg afterwards.

Ok, so I used your software to test out two SanDisk Thumb Drives - 32 GB - USB 3.0. According to your application, with one thumb drive, I am attaining write speeds between 30-40 MB/s and read speeds that are consistent at 165 MB/s. So I raided the two drives together using RAID 0 and got similar write speeds but my read speeds went up to 315 MB/s. Now, heres the kicker. The manufacture claims read speeds up to a maximum of 100 MB/s and write speeds up to a maximum of 40 MB/s. Here’s the other kicker. The USB 3.0 sticks are being tested in a USB 2.0 Port which is not supposed to operate beyond 60 MB/s. So how am I getting read speeds of 315 MB/s.

Not comprehensive because it doesn't show all compression ratios for BM Raw, or ProRes 422, etc. but it's a nice way to compare disk speeds and get an idea as to whether a drive will support the camera resolution that you want to use. I still recommend trying out a drive to verify.

Thanks to the developer for adding Apple M1 Mac support to this Disk Speed Test utility. I had previosuly run this on my new M1 Mac Mini, but results were slower than expected. I assumed it was due to running with Rosetta 2 emulation on the M1 Macs. Now that developer has added M1 Mac chip support, I am able to see how really fast my M1 Mac Mini SSD drive really is.

I really do not understand all of the negative reviews. I wanted to see the speed difference on various drives using various interfaces. This gave me the information I needed for free. The app does exactly what it says it will do in the product description.

This is an excellent way to test your ethernet speed. Mac Mini home server over ethernet 106MB/s. Qnap server on the same network write: 53MB/s, Read 98MB/s. Thunderbolt 2 Lacie external Hard drive 188MB/s write, 205MB/s read. My SSD on my mac main hard drive. 616MB/s write and 670MB/s read. This was the tool I needed to test my ethernet speed.

Does what it says it will quickly and I would guess accurately though I have no data to compare it to. provides raw data requireing analysis to determine useablility and not being computer savy the infromation is of marginal interest as I have nothing to compare it to.

Works fine on 12.4. Does it's job in terms of telling you what resoluion of video your drive can handle. That is all it's meant to do. As others have said, it doesn't stop on it's own. It's dumb, because it doesn't save the results for each "lap" the test runs.

I had no problems of any type installing an using on two hard drives. Both running Sierra. It quickly told me how much faster a new SSD drive was over my old drive. That is really all I wanted to know today. Yes an SSD is a lot faster. 5 times faster using a PCI adapter card an 2.5 times faster plugged into a drive bay. 2010 Mac pro.

Whatever people are saying it works perfectly on Catalina or Mojave. However it never stops runing and you must press hit the button to stop the process. Not sure it is the right thing to do but it is the only way to make it stop. A FAQ would been welcome to understand how it works.

Wanted to see if my cable to my external SSD was giving me full capacity speeds. It's also handy to give you a chart to tell you what your device was capable of handling. Easy to use interface.

I’ve launched from launcher and it did start. I did try once installed to click on open and it does not open as it would close immediately.

Most if not all bench tests stop themseleves once finished; and they also provide ample prompts and visual clues on what they are doing. With this app; however, you hit the big fat red START button and it never stops. That's right - it will just run forever and destroy your SSD's health. The start button also doesn't give any clue that the user needs to hit it again to stop the test!

It funcitons as expected. True the App tests Write and Read speeds almost continually. I guess that could be construed as annoying to some, but it's Quick and (hopefully) Accurate & best of all - FREE.

I'm running this on a Mac mini under Mojave. The only way I can stop a test once started is to quit the program. I must be missing something here. Otherwise it does the job.

Simple program that works smooth. The "help" in settings drop down explains how to use it if it's not obvious to you.

Once click start, it’s working well. Only thing needs to be noticed is once start clicked, it’s never stop, alternating between measuring write speed and read speed, need manually quit to stop it.

Not sure what people are talking about. Running the latest version of OS X, and this works just fine. Nice UI, great design - and it does exactly what I need it to (test my disk speeds)!

This just keeps running and never stops. I want it to run a test and then give me the results. Not run forever and never give me any actual scores. Also, making the target disk a little more obvious would help. It does get the job done but it isn't user friendly at all

Exactly what I needed to pinpoint read/write issues between a couple of drives. Super helpful for video editors for it includes resolution and format as criteria. No complaints at all!

I can't speak to the results, but it does run on /my/ MacBook. Side note: it also seems to run continously once you hit the test button... probably the intended behavior, but not exactly obvous.

Lots of reviews say it doesn't work. Maybe it was broken in the past but it works like a charm on Big Sur.

Seems to work fine with external drives but it will refuse to test your computer's internal hard drive. At least on Mac OS X. Gives out an error message that it needs, but doesn't have read/write permissions.

I think we’re at the point where we need to indicate higher than 4k file write and read speed. Other than that super useful

Fast for SSD drives even the internal drive. All you have to do to measure the internal startup disk is select your user directory rather than the whole disk.

Seemed to work at first. Ran read and write tests a few consecutive times then froze my Mac hard. Force close didn't work, restart didn't work...ended up uplugging the ssd without ejecting (beacuse eject wouldnt work either) to get it to sort of respond.

In late 2018 I’m still on Sierra. I never upgraded to High Sierra. Work IT dept. has advised against upgrading to Mojave yet. Seems to work fine.

13” rMBP, El Capitan, 1TB ssd internal, 1TB ssd Thunderbolt external, 13TB Thunderbolt I externals 5TB USB3 externals Indicates my USB3 drives run 25% faster than my T-Bolt I drives. Blackmagic is reporting my 7,200 rpm 3.5” enterprise drives are slower than a 5TB, 5,400 rpm 2.5” laptop drive in a USB3 enclosure. Not a chance based on my usage experience. I just dragged a 3.45gb folder of mixed files from my internal to both the T-Bolt I external and the USB3 external. T-Bolt was 40% faster.

Love this. Great for testing any drive really. Has saved me a ton of time.

This app is the standard for testing my drives before I trust them. Can you guys please make this an iPad OS app as well? That would be so freaking awesome.

Great FREE tool! Had an old ssd lying around and converted it into an external drive. Just needed a tool to read speeds and this is perfect.

Super easy to download, select a drive from the menu and run on a NAS drive.

Crashes on launch under OS X 10.6.8. Interestingly it runs fine on two other Macs. Many other people have reported the issue using different OS versions, so does not appear to be tied to 10.6.8. Issue goes back almost a year and has not yet been fixed. Odd.