How do I ... benchmark USB drives with CheckFlash?

CheckFlash is an easy-to-use USB flash drive benchmarking tool that can handle a few important tasks for administrators who need to know their devices are up to the job. Jack Wallen shows you how to run both the Read Stability and Write/Read tests on your USB flash drives.

If you're like me, you use USB flash drives for everything from data portability to portable operating systems to use for troubleshooting. There are instances when you want to know the read/write speeds of your USB drives or if the storage on the drive is stable. That task isn't easy without the right tools. CheckFlash is an easy-to-use USB drive benchmarking tool that can handle a few important tasks for those administrators who have a need to know their devices are up to the task.

In this introduction to CheckFlash, I will show you how to run both the Read Stability test and the Write/Read test on your USB flash drives.

This blog post is also available in PDF format in a free TechRepublic download.

Getting and installing

CheckFlash can be found at the developers' (Misha Cherkes) Web site. Download the zip file and save it to a known location. There is no actual installation of this tool; CheckFlash is a complete, executable binary file that can simply be double-clicked to launch.

The best thing to do is, upon extracting the zip file, move the ChkFlsh file to a location you will remember. The easiest thing to do is to right-click the ChkFlsh file and select the Add to Quick Launch Menu option. This will add a clickable button to launch the application in the Quick Launch bar that resides on the Task Bar. You could also select the Pin to Start Menu option to add an entry to your Start menu.

Once you have CheckFlash ready to launch, you can either go ahead and launch the application and then insert a USB flash drive or insert the drive and then launch the application. If you launch the application first, you will have to hit the refresh button in order to see your drive listed.

The application will open to the main window (Figure A).

Figure A

As you can see, this flash drive has an installation of Fedora installed.

Now you are ready to run some tests on your drive.

The tests

There are two tests and three actions you can take with this tool:

  • Read Stability Test: This test will determine if there are any errors on your drive as well as the read speed of the drive.
  • Write and Read Test: This test will determine the speed at which your drive can be written and read.
  • Low Level Initialization: This allows you to edit the partition information of the drive.
  • Save Image: This will save a binary image of your drive.
  • Load Image: This will allow you to load a previously saved image to the drive.
  • Full Erase: This will wipe the drive clean.

But before you select which test to run, you first have to select the Access Type for the drive. The only way to run the Red/Write stability test is to select the drive as either a logical or a physical drive.

Read Stability Test

The first test to undertake of your drive will be the Read Stability Test. Select the Access Type as Physical and then select the Read Stability Test. From there you have a couple of options. The options are related to how much testing you want to do on your drive. You can enact one full cycle of tests on your drive, you can choose "burn it," which will test until you manually stop the test, or you can manually select how many cycles to run. This will depend on how thorough you want your test to be. If you want only a cursory test, select a single cycle.

Once you have selected your test and options, click the Start button. During the test, the blocks on the right pane will fill up indicating how much of the test has occurred (Figure B). You will also notice a real-time read speed update near the bottom left corner.

Figure B

When the blocks are blue, the test is reading; when they are green, it is verifying.

Once the test is complete, you will get a simple report in the right pane. In the stability test, the report will only let you know if it found errors. You can get more information in the Information section of the window near the bottom left. This will tell you your average read speed of your drive.

Write and Read Test

Note: With the Write and Read test, all data on your device will be lost. The formatting of the drive will also be lost, so you will have to reformat the drive in order to use it again.

When you select the Write and Read test, you have to select the pattern type to use. There are two patterns to choose from:

  • Small Pattern Set: uses 55h and AAh patterns
  • Full Pattern Set: adds eight of "walking one" and eight of "walking zero" to the small pattern set
Once you have selected your options, click the Start button and your test will begin, as shown in Figure C.

Figure C

Uh oh, there are errors found on this drive.
This test will take a bit longer than the read-only test. When the test is done, your report will fill you in on what is up with your drive. As you can see in Figure D, my drive is filled with errors.

Figure D

These errors are all data write errors. This could be because the drive was formatted in the ext3 format instead of a Windows-compatible format.

Final thoughts

The USB flash drive is a tool that any IT pro could use on any given day. Knowing your flash drives are up to par with your needs is one way to make sure your tools will always be ready and able to assist you. CheckFlash is one of the handiest utilities available to keep your USB drives primed for action.

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Jack Wallen is an award-winning writer for TechRepublic and Linux.com. He’s an avid promoter of open source and the voice of The Android Expert. For more news about Jack Wallen, visit his website getjackd.net.


Is there any way to use this program to determine if the flash drive is USB 1.0, USB 2.0, or USB 2.0 high speed? I have a mix of a few hundred USB flash drives and I would like to sort them by the interface characteristics


Great article for this app. I use two flash drives for instant reference. Forget CDs, flash drives are A-OK. Just wish they would make 64-128 GB.


Problem is when launched, the Check Flash display shows the "start" button grayed out. So, no can do.


Large capacity flash drives may have good sequential read/write speeds (>20MB/sec for large file size) but quite often when you are working with a large number of smaller files or if you are doing random I/O (such as after moving your .PST file to the flash drive for portable Outlook). The write speeds drops to hundreds of KB/sec range. Some of the netbook users even found it useful to put their OS on a flash drive or SD card but found the performance to be less than acceptable due to slow small block random write speed. So it would be nice if CheckFlash could test an USB drive's 4K random write throughput.

Mark W. Kaelin
Mark W. Kaelin

How many USB flash memory drive do you have? Have you bench-marked them? How important is faster data transfer when it comes to portable storage like a flash drive?


It's not a problem that the start button is grayed out. Just select one of the 'Access Types' and the button becomes available.


You might want to add that it takes a LONG time to "write and read" test. 4gig drive being tested and... four hours later... still running test. Yikes!


Irrespective of size data encryption is paramount. I recommend Truecrypt. Some people feel that all drives should be encrypted, and it probably would have saved a few of those whose data were hijacked and ransomed.


Used to have 3-4 but just have one now that I purchased a 32 GB drive. Speed is important but less so than absolute storage size.


Sorry it took so long for reply. But I tried suggestion and it worked. Thanks

Neon Samurai
Neon Samurai

My last few downloads where in the 34 gig range with some much larger rainbow tables available still. There's no carrying those kinds of sizes around on small flashdrives. spanning multiple drives would mean having to reconstruct the singe data chunk any time it's to be used. I was actually thinking of getting an external platter drive for this and similar reference data needed across multiple platforms.


I love my new 32 GB thumb drive, but unfortuantely, I still carry around a 2.5" external. There's just no beating it. It's only a 120 GB but it's also a lifesaver in a pinch.

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