Choosing the Best Memory Card for Your Dashcam

An SD (Secure Digital) card is a compact, portable storage device that is commonly used to store data such as images, movies, and music in devices such as cameras, dash cams, smartphones, and tablets.

SD cards are useful because they allow for the easy transmission of data between devices as well as the storage of data when the device's internal storage is full. They can also be removed and replaced with a larger card, or stored separately as a backup.

With dash cams, we usually use a microSD card which is used in smaller electronic devices, though it may be used in any SD card slot with an adapter.

The best MicroSD cards to use for your dash cam should be at least a class 10 rank for speed and durability

The storage space requirement increases as the resolution gets higher. 4K images occupy much more space than 2K QHD, as it consumes more than full HD or 1080p images. This is also the reason why 4K dash cams like the VIOFO A139 Pro have maximized its storage space up to 512GB. Higher resolutions will also be more taxing on your SD card, so make sure you select an SD card that can handle that resolution with high-speed data writing.

Typically, recording one hour of 1080p video consumes around 6GB of storage. If you drive for two hours per day, five days a week, you would need approximately 64GB worth of memory.

If you’ve wired for parking mode, this will involve the camera recording for much longer to keep your vehicle protected, although in a mode to conserve space, either through only recording impact and motion, or at a lower frame-frate.

Consider the maximum storage capacity of your dash cam. New 2K dash cams, particularly those from VIOFO such as the A229 Plus and the A119 Mini 2 have increased their capacity to 512 GB, while some other cameras only have a 256GB maximum.

Moreover, dash cam memory cards undergo multiple overwrites. A larger memory capacity reduces the frequency of write-cycles and prolongs the card's lifespan.

When it comes to dash cam footage, the type of video file compression used can significantly impact both video quality and storage requirements. H.264 and H.265 are two common compression formats, with H.265 being the newer and better option.

When selecting an SD card for your dash cam, it’s crucial to choose one with the appropriate speed rating to ensure reliable performance. Look for a Class 10 or UHS-I (U1) rating, which guarantees a minimum write speed of 10MB/s, which will work for all cameras rated 4K and below. Typically, a 4K camera records approximately 3.75MB/s. A 2K camera records at about 2.5MB/s, combining to roughly 6.25 MB/S total, making a Class 10 card(10MB/s) ideal.

That being said, “faster SD cards” won’t necessarily improve video quality, nor durability. Remember: dash cams don’t require the highest speed rating - rather, they require something reliable that meets the requirements of the image quality.

A 32GB card is great value for those who use their dash cams for driving recording. Typically, this translates to about 3-4 hours of 1080P recording, which is more than enough for most drivers.

When a dash cam records continuous driving, it also divides the footage into smaller increments or segments to make it easier to manage files in storage (Normally 1-2 minute clips, depending on the unit). The loop recording feature is also helpful in maximizing your storage space. So, if the primary purpose of your dash cam is to record your daily commute essentially, you can go for a full HD dash cam like the BlackVue DR770X, the Thinkware F70 Pro, or the Thinkware F200 Pro.

When using a parking mode dash cam, opting for a 64GB SD card or higher enhances durability and extends parking recording time. Adequate storage is crucial to prevent overwriting before you return to your vehicle. Most parking modes offer multiple recording options to conserve space, like time-lapse mode, which condenses 30 minutes of footage into 5-minute clips, or impact/motion detection, which records only when triggered.

Our most popular option is the 128GB SD card, preferred for its capacity to retain footage longer. Additionally, Thinkware dash cams feature memory partition feature, allows you to prioritize parking mode files over standard driving footage, ensuring crucial events are saved longer.

Rideshare drivers may want to use the larger 256GB card so as to keep the most amount of video storage in case of any issues with previous customers. This is especially true if running a 3-channel setup, as recording on 3 devices at once will take up more space.

As some rideshare drivers or fleets may want multiple days worth of backlogged footage, the fact that dash cams generally overwrite footage naturally can be a detriment. If this is the case, then using this larger card, and swapping it out for another after a shift is recommended, while offloading footage to a local storage device or PC.

The higher the resolution, the greater the storage space requirement. If your dash cam is recording 4K UHD resolution, uses multiple channels, and activates parking mode recording, a 512 GB micro SD card should be considered.

How much video can an SD card hold? This is a question we get all the time and the answer depends on two factors: the SD card size and the dash cam's bit rate. Based on our testing, here’s a table of the estimated recording hours of dash cams based on the SD card size. Please note these numbers are just estimates, and other factors can cause them to vary.

For the Thinkware U3000, the maximum bitrate for the front camera is 30Mbps, while the rear camera records at a 10Mbps bitrate. Therefore, they have a total of 40Mbps for both cameras. Below are the estimated recording hours based on various SD card sizes:

These tables show the available recording lengths for BlackVue dashcams. For the BlackVue DR770X series, the maximum is 25Mbps for the front, and 10Mbps for the secondary cameras like rear and interior. On the other hand, the new BlackVue DR970X Plus series’ bitrates have been upgraded to a maximum of 60 Mbps for the front, and 10Mbps for the rear.

These tables show the recording lengths for the new VIOFO dash cams – the VIOFO A119 Mini 2, the A229 Plus, and the VIOFO A229 Pro. All these dash cams have a maximum storage capacity of 512 GB.

The numbers here are based off of the highest bitrate and recording quality available for each respective model, which can be decreased to better fit your preference, and allow for longer storage.

Dash cams perform drastically more recording when compared to a standard camera. This combined with the constant video looping and high image quality of many units, will result in eventually consuming a standard-issue SD card.

Of course, cheap SD card brands will be consumed quicker, this is why we recommend reliable brands such as SanDisk or Samsung brand SD cards. An SD card will last, on average 1-2 years in a dash cam. This is perfectly normal, and one reason a backup SD card is recommended, leading us to our next point.

To ensure the health of your card, we recommend formatting your SD card once every 2-3 months. This will ensure there are no corrupted files or manual recordings stuck on the SD card, causing errors or shortening the loop cycle.

BlackboxMyCar is proud to say that all the microSD cards we offer have been rigorously tested to ensure compatibility and to offer the longest lifespan as well. 

Our third-party microSD cards go through the same quality testing and are a more affordable option for SD card options. No matter what card you buy from us, all of these are covered under a 1-year in-house warranty so you can be rest assured that we’ll resolve any issues that you may come across.

Due to Dash Cam's naturally aggressive read/write cycles, use of an SD card inside will very frequently invalidate the manufacturer's warranty. But not ours! Rest assured you'll still be covered when shopping with BlackboxMyCar

If you have any further questions, comments or suggestions, then don't hesitate to reach out to our product experts today!

In addition, we recommend all of our customers purchase a smaller 16GB or 32GB card to be kept in your vehicle at all times. The reason is because they can be used in case your SD card in the unit fails or you’re away on a trip and won’t be able to save or review the footage in time before it gets overwritten. You’ll be able to swap your cards out instantly and keep recording without worrying that important footage will be deleted.