With so many types, standards, and speed classes of SD cards, you may find it hard to decide which SD card you actually need for recording videos.

In this article, I’ll explain you all about the various standards of SD card speed and classes.

You’ll also get a quick recommendation of a few fast SD cards that are good for general video recording videos (up to 4k) with most cameras and GoPros.

 

Speed Class Standards


Recording videos requires a constant minimum write speed to avoid ‘frame drop’ while you’re recording. A “fast” SD card would ensure a smooth video recording as well as proper playback. The SD Association has defined various Speed Class standards. This is mainly useful for camcorders, video recorders and other devices with video recording capabilities.

There are three kinds of SD Card speed indications:

  1. Speed Class
  2. UHS Speed Class
  3. Video Speed Class

These speed classes are labelled on the front side of each SD memory card. The labelling is in the form of little numbers with a circle, a U shape, or a V shape. The manufacturers use these “classes” to determine the speed of the memory card.

Speed Class

The Speed Classes include: Class 2, 4, 6 and 10. Class 2 cards are the slowest and class 10 cards are the fastest. The class number refers to the minimum write speeds in megabytes per second (MB/s), so Class 2 = 2MB/s, Class 4 = 4MB/s, Class 6 = 6MB/s, and Class 10 = 10MB/s.

UHS Speed Class

The UHS Speed Classes are UHS Speed Class 1 (U1) and UHS Speed Class 3 (U3). On the top high-end cards, the speed class rating is designated with a U symbol. U1 supports at least a 10MB/s write speed (like a Class 10), and U3 cards offer at least a 30MB/s write speed. If you shoot in 4K, you need a minimum U3 SD card.

UHS Speed Class has another classification as well. It includes UHS-I, UHS-II & UHS-III. This classification refers to the absolute top theoretical speed of the SD card, instead of the minimum speed. It’s a good way to gauge burst shot speeds. UHS-I Cards have a maximum speed of 104 MB/s, while UHS-II cards have a maximum speed of 312 MB/s. The newer UHS-III Cards theoretically support up to 624 MB/s, but aren’t widely available yet.

Video Speed Class

The Video Speed Classes include V6, V10, V30, V60 and V90. For 4K, a video speed class of V30 or more is ideal.

Have a look at the graphic below to understand the minimum sequential write speed you’ll get with each SD Card speed class. It also has the recommended corresponding video format for different speed classes.

video speed class

Graphic Source: SD Association

From this graphic, it’s clear that if you’re looking to record standard definition videos, SD cards with specifications Class 10, U1 & V10 are sufficient. For HD/Full HD video recording, you need up to U3, V30 rating. For 4K videos, you need an SD card with video speed class V30 and above. Lastly, for 8K video recording, you need at least a V60 video speed class rating.

 

Recommended SD Cards for 4K Video Recording


It’s generally a good idea to get a high-speed SD card, especially if you are shooting in RAW or filming high-resolution videos. An SD card that offers a minimum of 30MB/sec write speed is sufficient for recording in 4K. So, for 4K, a video speed class of U3, V30 or more is ideal.

Here are the top three recommended SD Cards for smooth and hassle-free 4K Video Recording:

SanDisk Extreme UHS-I SD Card

  • Brand: SanDisk
  • Speed Class: UHS-I, U3, V30
  • Maximum Read Speed: 160MB/s
  • Maximum Write Speed: 90MB/s
  • Storage Capacity: 32GB, 64GB, 128GB, 256GB, 400GB, 512GB, 1TB
SanDisk 256GB Extreme microSDXC UHS-I Memory Card with Adapter - Up to 160MB/s, C10, U3, V30, 4K, A2, Micro SD - SDSQXA1-256G-GN6MA
  • Up to 160MB/s read speeds to save time transferring high res images and 4K UHD...
  • Up to 90MB/s write speeds for fast shooting; Requires compatible devices capable of...
  • 4K UHD and Full HD Ready with UHS speed class 3 (U3) and video speed class 30 (V30)

The SanDisk Extreme UHS-I SD Card is arguably the most popular SD card and our top recommendation for recording 4K videos. With its awesome write speeds of up to 90 MB/s and read speeds of up to 160 MB/s, you can easily capture Full HD, 4K videos, as well as raw and burst photography with your camera.

Available in 32GB, 64GB, 128GB, 256GB, 400GB, 512GB and 1TB sizes, the SanDisk Extreme SD Card is ideal for recording extreme sports and other fast-action activities.

SanDisk Extreme PRO UHS-I SD Card

  • Brand: SanDisk
  • Speed Class: UHS-I, U3, V30
  • Maximum Read Speed: 170MB/s
  • Maximum Write Speed: 90MB/s
  • Storage Capacity: 32GB, 64GB, 128GB, 256GB, 512GB, 1TB
[Older Version] SanDisk 128GB Extreme PRO SDXC UHS-I Card - C10, U3, V30, 4K UHD, SD Card - SDSDXXY-128G-GN4IN
  • This version has been discontinued by manufacturer
  • Shot speeds up to 90MB/s, transfer speeds up to 170MB/s [requires a compatible device...
  • Based on internal testing; Performance may be lower depending upon host device,...

With top notch read (up to 170 MB/s) and write speeds (up to 90MB/s), the SanDisk Extreme PRO is one of the fastest UHS-I microSD cards. With these speeds, you can smoothly capture burst photos, 4K videos and access many other features of your camera without any hassle.

SanDisk Extreme PRO UHS-I SD Card comes in 16GB, 32GB, 64GB, 128GB, 256GB, 512GB and 1 TB variants. It’s built for and tested in harsh conditions, which is why it’s temperature-proof, waterproof, shock-proof, and X Ray-proof.

Lexar Professional UHS-II U3 1000x SD Card

  • Brand: Lexar
  • Speed Class: UHS-II, U3, V60
  • Maximum Read Speed: 150MB/s
  • Maximum Write Speed: 90MB/s
  • Storage Capacity: 32GB, 64GB, 128GB, 256GB
SPECIAL SALE
Lexar Professional 1000x 128GB microSDXC UHS-II Card w/ Adapter, Up To 150MB/s Read (LSDMI128CBNA1000A)
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Lexar Professional 1000x 128GB microSDXC UHS-II Card w/ Adapter, Up To 150MB/s Read (LSDMI128CBNA1000A)
  • High-speed performance—leverages UHS-II technology (U3) for a read transfer speed...
  • Premium memory solution for sports camcorders, tablets, and smartphones
  • Designed for high-speed capture of high-quality images and extended lengths of 1080p...

Designed for DSLRs, action cameras and drones, the Lexar Professional 1000x leverages UHS-II technology (U3) for an optimum read transfer speed. It’s capable of providing amazing read speeds of up to 150 MB/s and write speeds of around 90 MB/s, making it perfect for high-speed capture of high-quality images and extended lengths of 1080p Full-HD and 4K video.

Lexar Professional UHS-II U3 1000x SD Card backwards compatible and works at the highest UHS-I speeds if your camera supports only UHS-I SD cards.  It comes in multiple sized variants: 32GB, 64GB, 128GB and 256GB.

Samsung EVO Select V30 

  • Brand: Samsung 
  • Speed Class: UHS-I (U3), Class 10, V30 
  • Maximum Read Speed: 100MB/s 
  • Maximum Write Speed: 90MB/s 
  • Storage Capacity: 32GB, 64GB, 128GB, 256GB, 512GB 

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SAMSUNG EVO Select Micro SD-Memory-Card + Adapter, 256GB microSDXC 130MB/s Full HD & 4K UHD, UHS-I, U3, A2, V30, Expanded Storage for Android Smartphones, Tablets, Nintendo-Switch (MB-ME256KA/AM)
  • ALL THE SPACE YOU NEED: Store tons of media on your phone, load games or download...
  • FAST AND SMOOTH: With superfast U3, class 10 rated transfer speeds of up to...
  • EXPAND AND STORE BIG: Find your perfect fit from 64GB, 128GB, 256GB and 512GB; Select...

If you’re looking for a reliable memory card, the Samsung EVO Select UHS-I microSD Card is definitely worth considering. It offers impressive read speeds of up to 100MB/s and write speeds of up to 90MB/s, making it ideal for capturing 5.3K or 4K UHD videos and high-resolution photos.

With storage capacities ranging from 32GB to 512GB, the Samsung EVO Select microSD card provides ample space for your media files. Additionally, it’s built to withstand various environmental conditions, as it is shockproof, waterproof, temperature-proof, X-ray proof, and magnetic-proof. Overall, this microSD card is a solid choice for anyone looking for fast and reliable storage for their GoPro HERO11 Black.

ADATA Premier Pro V30

  • Brand: ADATA
  • Speed Class: UHS-I (U3), Class 10, V30 
  • Maximum Read Speed: 100MB/s 
  • Maximum Write Speed: 80MB/s 
  • Storage Capacity: 64GB, 128GB, 256GB

ADATA 256GB Premier Pro microSDXC/SDHC UHS-I Memory Card with Adapter - C10, U3, V30, 4K, A2, Micro SD - AUSDX256GUI3V30SA2-RA1 (256GB)
  • 256GB capacity SD 6. 0
  • Up to 100MB/80MB per sec* Read/ write speed based on ADATA internal testing;...
  • Uhs speed: Class 3, speed Class: Class 10, video Speed Class: V30, application...

The ADATA Premier Pro microSD card is an excellent choice for action cameras, with its V30 qualification allowing for minimum recording speeds of 30MB/s. With maximum read/write speeds of up to 100MB/80MB/s (based on internal ADATA testing), this SD card is sure to handle high-quality video recording and photo capture with ease.

Available in 64GB, 128GB, and 256GB sizes, the ADATA Premier Pro microSD card is designed to withstand various extreme conditions, including water, shocks, X-rays, anti-static, and extreme temperatures. These features make it a reliable and durable option for adventurers who want to capture their experiences with confidence.

 

What SD Cards Have The Fastest Write Speeds?


The fastest SD Cards available on the market are:

  1. SanDisk Extreme PRO SDXC UHS-II: This card boasts write speeds of up to 260 MB/s and read speeds of up to 300 MB/s. It is ideal for high-resolution photography and 4K video recording.
  2. Lexar Professional 2000x SDHC/SDXC UHS-II: With write speeds of up to 260 MB/s and read speeds of up to 300 MB/s, this card is also designed for high-resolution photography and 4K video recording.
  3. Sony SF-G Tough UHS-II SDXC: This rugged card offers write speeds of up to 299 MB/s and read speeds of up to 300 MB/s, making it suitable for professional photographers and videographers.
  4. ProGrade Digital SDXC UHS-II V90: The ProGrade Digital SD card features write speeds of up to 250 MB/s and read speeds of up to 300 MB/s, perfect for high-resolution photography and video recording.
  5. Delkin Devices Power UHS-II (V90) SDXC: This card provides write speeds of up to 250 MB/s and read speeds of up to 300 MB/s, making it a reliable choice for professional applications.

These SD cards are compatible with devices that support the UHS-II standard, which enables faster write speeds compared to the UHS-I standard.

Keep in mind that the actual performance of these cards may vary depending on the device you’re using. Always check your device’s compatibility and recommended SD card specifications before purchasing a high-speed SD card.

 

Is V30 Enough For 4K?


Yes, a V30-rated SD card is generally sufficient for 4K video recording. The V30 designation means that the card has a minimum sustained write speed of 30 MB/s. This speed is adequate for most consumer-grade 4K recording scenarios, which typically require write speeds between 30 MB/s and 100 MB/s, depending on the bitrate and compression format used.

However, if you are working with professional-grade 4K video recording equipment or need to record at higher bitrates, you may want to consider cards with higher speed ratings, such as V60 (minimum sustained write speed of 60 MB/s) or V90 (minimum sustained write speed of 90 MB/s). These higher-rated cards provide additional performance headroom for more demanding 4K video recording applications.

Always check your device’s specifications and requirements for SD cards to ensure you choose the right card for your needs.

 

What is The Write Speed of a 128GB SD Card?


The write speed of a 128GB SD card varies depending on the specific card model and its class or speed rating. SD cards are available in different speed classes, such as Class 10, UHS-I, UHS-II, and UHS-III, as well as Video Speed Class ratings like V30, V60, and V90.

Here are some examples of different speed ratings and their respective write speeds:

  1. Class 10: Minimum write speed of 10 MB/s.
  2. UHS-I (U1): Minimum write speed of 10 MB/s.
  3. UHS-I (U3): Minimum write speed of 30 MB/s.
  4. UHS-II (U3): Minimum write speeds ranging from 30 MB/s to over 200 MB/s, depending on the card model.
  5. UHS-III: Minimum write speeds up to 624 MB/s, depending on the card model.
  6. V30: Minimum sustained write speed of 30 MB/s.
  7. V60: Minimum sustained write speed of 60 MB/s.
  8. V90: Minimum sustained write speed of 90 MB/s.

When selecting a 128GB SD card, check the card’s speed rating and your device’s specifications to ensure compatibility and optimal performance. Keep in mind that the actual write speed may vary depending on the device and the specific use case.

 

What SD Card Speed do You Need for Video Recording?


After reading this article, you must have an idea of how important the SD card speed is for video recording. If you don’t have a fast memory card in your camera, it may adversely impact your camera’s performance and videos files may fail to save. The SD card speed you need for video recording depends mainly upon the bitrate of the video.

Generally, the higher the resolution and frame rates, the higher the bitrate. So, as a general rule of thumb, if you’re shooting at high resolutions (eg. 4K) or high frame rates (eg. 240fps) go for a minimum of U3, V30 card.

 

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