Aug 1st, 2017: Changed the budget recommendation to Transcend’s 400X. Changed the top pick alternative to the Sandisk High Endurance. Lexar cards previously occupied these spots but with decreased reliability and with Lexar’s exit from the consumer flash market we are making needed changes.
July 9th, 2017: Just purchased the 64GB Sandisk High Endurance for testing. Reviews and reports on the Sandisk High Endurance card have been much stronger compared to Lexar’s High Endurance offering. We may change our recommendations.
May 28, 2017: We no longer recommend the Lexar 633X due to increased reports of failures in dash cameras. We are looking for a new budget recommendation.
Jan 17, 2017 : Lexar Endurance is now our alternative to the Transcend High Endurance.
Video Guide to SD Cards
What Type – SD or microSD?
There are two physical sizes, SD and microSD. We recommend the microSD size even if your camera takes the larger full size SD card. Nearly all microSD cards include a full SD adapter so it’ll work with your current camera. When you change cameras you won’t have to buy a new card as the vast majority of dash cameras use microSD cards.
How Much Space?Next the amount of space. 32GB is the sweet spot for value. That’s 3-4 hours of 1080P recording which is more than enough for most drivers. Any less and you pay more money per gigabyte and save only a few dollars.
What Speed Rating?Look for: “Class 10” OR “UHS-I U1” rated microSD card. Slower cards can cause recording problems. See the symbols below for what to look for. Some cards have both ratings and that’s OK.
Speed ClassThe speed class symbol represents the minimum writing speed to the SD card in megabytes per second. Class 10 is the highest speed at 10 megabytes/second.
UHS Bus & ClassUHS improves on Class 10 cards by providing a faster interface for compatible devices. Most dash cameras don’t use the UHS interface but UHS cards will still work properly. There are two separate ratings, the Bus & Class. The UHS Bus is the transfer speed and has two tiers: UHS-I (50MB/S) and UHS-II (156 or 312 MB/S). The UHS Speed Class also has two speeds minimum writing speeds: U1 (10 MB/S) and U3 (30 MB/S)
Faster SD Speeds Won’t Improve PerformanceCurrently 1440P is the largest resolution and only requires 1/3rd of the max transfer rate of Class 10 cards. Only 4K recording at very high bitrates will need an upgrade to U3 or UHS-II and that’s years away.
Picking the Right Memory Type
One of the most important but least known characteristics of SD cards is the NAND type. The NAND type describes how the physical cells that store information were constructed.
TLC & MLC NAND Overview
Consumers typically see two types of flash memory – TLC and MLC.
TLC is cheaper and less reliable. Manufacturers increased storage density by stuffing more information (3 bits/cell) into a memory cell but sacrifices durability. MLC costs more money and is far more durable because it stores less information per cell (2 bits/cell) so wear and tear is greatly reduced. If you want the science behind NAND cells read it here.
Flash Memory – It Eventually FailsWriting data to a SD card physically and permanently damages the NAND chip. Overtime this causes the SD card to fail which can write lock the card preventing your dash camera from recording. TLC cards can overwrite itself 500 times before experiencing failures, a MLC card between 1500 to 3000 times.
Why this MattersYour dash camera constantly writes to the memory card and adds a lot of wear and tear not found in other uses such as a secondary storage for your cell phone. MLC cards often have better error correction, wear leveling and controller chips which increase performance and lifespan.
Our SD Card RecommendationsWe focus on MLC cards as it’s only a few dollars extra for significantly increased reliability and peace of mind.
Our top recommendation is Transcend’s High Endurance line. For 32GB cards they quote 6,000 hours of 1080P recording or 2,197 write cycles before experiencing problems. It’s an excellent balance between price and durability. Transcend also uses these cards for their own DrivePro dash cameras.
Transcend’s cards are also used by Novatek’s engineers when testing their image processors. Novatek processors are found in many popular cameras such as the G1W, A118C, Viofo A119 and the Street Guardian SG9665GC. We think this gives greater assurances around compatibility and performance if you use a Transcend card over other brands.
We now recommend Transcend’s 400X even though you lose the warranty when used in dash cameras. The 400X is recommended by a number of manufacturer’s we trust including Vicovation & Street Guardian – both design cameras for hot weather. The 400X has a better history of reviews compared to other alternatives. It also has error correction codes we think contribute to its great durability. We could not find a good alternative with a warranty that had a history of use with dash cameras (Samsung voids warranty).
Sandisk has their own dash cam specific memory cards. Its ratings have been excellent on Amazon in the 2 years since it has been released. As well it’s often cheaper and has better availability than the Transcend High Endurance around the world. While Transcend’s card has better lifespan we think the Sandisk card is still a great choice.