Blackmagic Disk Speed Test 4+

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.