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Best SD Card for 4K Dash Cams

Best SD Card for 4K Dash Cams

So, you got a new dash camera for Christmas! Yay! The excitement of unboxing your new dash cam and the anticipation of capturing all the adventure that awaits ahead - and then you realized the dash cam doesn’t come with an SD card. What a bummer! You type ‘microSD card’ onto Amazon and boom! Over 5,000 results! Yah, we hear ya.

Do not fear and no need to panic, we’ve got you covered!

Why do I need a microSD card?

An SD card, short for Security Digital Card, is how footage files are stored in your dash cam. A microSD card is simply a smaller SD card - about the size of your fingernail. But don’t be fooled by its size, microSD cards are capable of storing up to several gigabytes of information and play an extremely important role in the proper functioning of your dash cam. Did you know that many common dash cam problems, such as camera freezing or random powering off, can be attributed to a malfunctioning SD card?

Does speed matter?

SD cards come in different speed classes. Speed classes are essentially ways to classify the write speed of the SD card. In many applications and devices, the read speed and write speed of the SD card is essential because it dictates how fast the device can write, store and transfer data.

The 10 in Class 10 stands for 10 megabytes per second and it simply indicates the minimum write speed of the SD Card. You might have seen the UHS Speed Class on other SD Cards. UHS stands for Ultra High Speed and it also measures the minimum writing speed, but more specifically for recording video. A UHS-I U1 and the Speed Class 10 both indicate a write speed of 10 megabytes per second.

Generally, you want an SD card that is at least a Class 10 - anything less and you might end up with a choppy, laggy recording. But you don’t need to run out and buy the fastest SD cards (ie. UHS-I U3) because fastest doesn’t necessarily improve video quality nor durability. A Class 10 or UHS-1 is quick enough to handle even the most demanding dual-channel dash cam systems like the BlackVue DR900S-2CH or the VIOFO A129 Pro Duo.

Got a Thinkware U1000 Dual Channel dash cam? Because the U1000 offers 4K in the front camera and 2K in the rear camera, you can opt for a UHS Class 3 SD card, like the Samsung Evo Plus. But be sure not to use a UHS-I U3 card in a Full HD dash cam - the main board may not be designed to process faster than Class 10 or UHS-1 card and the dash cam may heat up excessively.

Does size (capacity) matter?

You bet! A higher capacity memory card means more data can fit onto the card before it runs out of room to store new data. This is particularly important because of the dash cam’s loop recording function.

Higher capacity = more room for more data = recording more data before overwriting kicks in

For example, say you have a 16GB microSD card, which gives you about a bit over an hour of recording for your Thinkware U1000 Front-only dash cam. Now, say your commute to and from work is typically 45 minutes each way (in other words, you drive about 90 minutes per day). That’s 1.5 total writes a day on the SD card. If the SD card you have is good for 500 total writes, that’s 333 days and you will be needing to replace the SD card right about next Black Friday.

The less overwriting your dash cam makes, the longer the SD card will last.

Now, before you run out and buy the highest capacity SD card you can find, check your dash cam’s user manual or the product information page on BlackboxMyCar first - the maximum supported capacity varies from dash cam brands and models. There really is no point in getting a 256GB for a Thinkware M1 when the maximum it can support is 64GB, is there?

Want to know how much video (in minutes) will an SD card hold? Check out our Recording Capacity of SD Cards chart.

Does price matter?

Yes, it does, because the price will affect whether an SD card is worth buying. Try to avoid cards that are too cheap. Too good to be true? Yes, chances are if the card is too good to be true, it usually is, and there is an abundance of bad, counterfeit/fake SD cards on the market. Here’s a good article to learn more: How to tell if a SanDish SD card is fake?

And just as you would stay away from uber-cheap SD cards, avoid overpriced cards, too. Companies like BlackVue, Thinkware and VIOFO have their own branded-SD cards. They are often marketed as best for compatbility. Unfortunately, the majority of these branded cards cost more than the comparable Samsung, SanDisk or Transcend card. We have been using SanDisk and Transcend SD cards in all of our dash cams and we have yet to encounter any compatibility issues.

MicroSDHC vs microSDXC card

SDHC stands for Secure Digital High Capacity, come preformatted with the FAT32 file system. SDXC stands for Secure Digital eXtended Capacity. SDXC adopts Microsoft’s exFAT file system as a mandatory feature.

What does it all mean? There really is no difference in quality or security or speed. SDXC cards are simply higher-capacity version of the SDHC, which is a higher-capacity version of the original SD card.

How long would the microSD card last?

Like we mentioned earlier, the less overwriting the longer the SD card will last. Dash cam SD cards wear out faster than any other camera because the dash cam is constantly writing and rewriting on the SD card and if your SD card fails your dash cam stops working. That’s the bad news. The good news is that the SD card’s lifespan is usually measured in many, many thousands of write cycles, and the SD card uses a special algorithm that balances the wear across the entire card’s cells.

On the SD card, you will find another set of codes, such as MLC on the BlackboxMyCar High Endurance microSD card. MLC stands for Multi-Level Cell, which is a memory technology that the SD card uses to store information. MLC cards are designed for long-term reliability. These cards are designed to last for about 10,000 write cycles. MLC cards also have better error correction, wear-leveling, and controller chips, which increases performance and lifespan.

You may also find SD cards that are TLC. TLC stands for Triple Level Cell. These cards are typically cheaper but less reliable for dash cams because of considerably shorter write cycles. These cards will work with your dash cam, but after about 3000-5000 write cycles, it will start to show signs that the end of the lifespan is approaching and you will be needing to replace the SD card soon.

How many microSD cards do I need?

While your dash cam can only write onto one SD card at a time, we recommend you keep an extra SD card as a spare for cases like:

  1. Accident - you can easily swap your cards out and keep recording without worrying that you’ll overwrite important footage.
  2. Faulty Card - you’ll be protected in case your current card has any problems.

The backup SD card doesn't have to be of high capacity, a small 32GB would definitely do.

How to choose the best SD card for a 4K UHD dash cam?

1. Maximum supported capacity - A 4K @30FPS one-minute video takes about 450MB of memory, we recommend using a SD card with the highest capacity allowed by your dash cam. That’s 128GB for the Thinkware U1000 Dual-Channel, and 256GB if you have the BlackVue DR900S-2CH or VIOFO A129 Pro Duo.

2. High endurance card - High endurance card (ie. MLC cards) are designed for long-term reliability. These cards are designed to last more write cycles, and have better error correction, wear-leveling, and controller chips, which increases performance and lifespan.

3. Last but not least, do note that due to the 4K video size, viewing video right from the SD card will appear choppy and laggy. In other words, before you chuck the dash cam or microSD card out thinking they failed you, try transferring the video file onto your computer (either transfer via WiFi or by physically plugging in the microSD card into your computer using an sd adapter/card reader) and view again - that might make all the difference.

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