Free Tools to Check SD Card Speed and Capacity

SD and microSD cards are used for storage in a variety of applications. From cameras to Raspberry Pis, phones, dashcams, and the Nintendo Switch, sooner or later you’re going to need an SD card for something. Unfortunately, there are a lot of fake SD and microSD cards floating around on the Internet. Even reputable online marketplaces like Amazon aren’t immune to the influx of useless cards being flogged to unsuspecting consumers.


Sometimes these fake cards are from no-name brands; other times they’re counterfeits of recognizable and trusted brands. Either way, they scam buyers in one of two ways. The most common is falsely stating the card’s capacity. For example, a card is advertised as 256 GB; however, it really only holds 4 GB. In some cases the card corrupts data, rendering it useless. Fortunately, there are a number of free tools that can test the speed and capacity of your cards. Before you order a large batch of super cheap SD cards, buy one and test it to make sure you’re getting what you pay for.


H2testw has been around for a very long time and for good reason. This reliable tool is able to test the true capacity of an SD/mircoSD card, as well as the read/write speed of the drive. The only downside to H2testw is the fact that it is quite old. This means that the software has not been optimized to be used on larger-capacity drives. While H2testw will work on any size drive, it may take a bit longer to complete the test.


H2testw was originally developed by a German software engineer. As such, the website that hosts the software, as well as the software itself, is in German. However, don’t let that scare you. Downloading the installer from the website is self-explanatory, regardless of your German language skills. Once downloaded, simply run the installer. After the first run it will give users the option to use English as the default language. H2testw is only available on Windows; however, it can be run on Linux and Mac via a virtual machine.


If you’re looking for something a bit speedier than H2testw, consider FakeFlashTest. This tool is very similar to H2testw in that it writes data to your SD card in order to determine read/write speed and capacity. However, FakeFlashTest speeds up the process by offering a  “Quick Size Test.” This function writes and reads 512 bytes of data at random sectors across the card. This enables much faster test results, which is particularly ideal for larger capacity cards.


It should be noted that the “Quick Size Test” is destructive, meaning that any data on the card will be wiped. There is an option to test a card without resulting in data loss; however, it takes much more time to complete. We strongly suggest that you back up any data, regardless of which test you opt for.


Whereas both FakeFlashTest and H2testw write data to the SD card in order to determine capacity, ChipGenius doesn’t write any data at all. Instead, ChipGenius locates the vendor (manufacturer) information as well as storage information found programmed into the SD card storage. It then cross references this information with a database and reports the findings back to you. So if you purchased a 64GB SanDisk, but ChipGenius reports that it’s really an 8GB Emtec, then you know you’ve been had. The advantage of this is that the test process is much quicker, as ChipGenius isn’t reading or writing any data.


Unfortunately, selling fake or counterfeited SD cards is big business. This means that shady sellers are becoming more sophisticated, which allows them to cover their tracks. As a result, ChipGenius won’t be able to sniff out every fake card floating around on the Web, just the poorly programmed ones.

Blackmagic Disk Speed Test

If you’re a Mac owner and want to verify your SD cards, Blackmagic Disk Speed Test is for you. This free utility was designed to test the speed of larger drives; however, it will also work on SD and microSD cards. The only downside is  that Blackmagic Disc Speed Test was designed for people working with large files, such as video clips.


Consequently, the app writes large blocks of data to your storage device and then reads that data to verify performance. Unfortunately, this means that the test takes quite a bit of time to complete.

Which tools do you use to verify the speed and capacity of your SD cards? Let us know in the comments!


    1. The chipgenius official page is in chinese (bbs mydigit). You can use google translate to see it in english, or just get the file from softpedia instead. Everywhere else is probably untrustworthy. Always scan files with an antivirus before you run them, or upload the file to virustotal

Comments are closed.