U3 vs. U1 SD Cards: A Detailed Comparison (2023)

SD cards are small flash memory cards or storage devices designed as high-capacity storage for various portable devices such as car navigation systems, cell phones, digital cameras, digital camcorders, and computers.

SD cards offer excellent compatibility with many electronic devices. They make transferring data from one device to another extremely convenient.

It is essential to buy the right SD card according to your needs. You need to check the storage capacity, speed class, and physical size. It's important to buy the right SD card as well to avoid equipment malfunction or even worse data loss.

Taking all of the above into account, U3 offers more in terms of storage capacity, speed class, and video class compared to U1.

This article provides a detailed comparison between the U1 and U3 SD cards. So let's get started.

U3 vs. U1 SD Cards: A Detailed Comparison (1)

Micro-SD-Karte UHS-1

The fastest SDXC memory cards have the ultra-high speed rating, represented by a number inside the letter "U." U1 means the speed rating is 10MB.

This card offers fast transfer speeds of up to 104MB.

SanDisk primarily used the UHS-1 card, which greatly increased transfer speeds. As of now, UHS-1 is commonly used for many Micro SDHC and Micro SDXC cards, such as the SanDisk Ultra SD UHS-1 card.

Micro-SD-Karte UHS-3

UHS-3 adds a second row of pins. It offers a higher transfer speed of up to 312 MB.

The design of UHS-3 is dual rail and LVDS technology, which greatly improves the performance of the SD card.

It also uses a QR feature, also known as quick recovery, to optimize power management, which in turn helps the SD card reduce the time it takes to transition from sleep to wake.

Because it can optimize a camera's power consumption, the UHS-iii is well-suited for shooting time-lapse or longer video.

Difference Between Micro SD U1 and U3

UHS speed class

Two classes of ultra-fast memory are now more common: U1 and U3. But many of the higher end cameras require at least one U3 for many features. Let's compare them and see which micro SD card is your ideal choice.

Comparing U1 vs U3, the main difference between UHS-i Class 1 and Class 3 cards is that UHS-i Class has 10MB write speed and Class 3 has 30MB write speed.

This is a significant difference and particularly critical when recording large amounts of data quickly, such as in B. Recording 4K video.

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If you're shooting with a small sensor, or just taking street or portrait shots, speed may not matter much.


Other than UHS speed class, there is something else called UHS bus. The UHS bus type is the Roman numeral on the front of the card. The UHS bus refers to how data is transferred between the pins on the card and the connector on the host device.

The UHS bus is UHS-i, UHS-ii, or UHS-iii with maximum theoretical transfer rates of

170MB, 312MB and 624MB. However, the UHS bus only refers to the clock speed of the card and not the transfer rate.

So if you compare UHS-1 and UHS-3, UHS-3 is four times faster than UHS-1, but only on devices that support additional pins.

UHS-1 and UHS-3 have a single row of pins on the back of the card, which means that the data transfer speed can reach around 100MB and 400MB.

However, the UHS-3 card has a second row of pins on the back of the card, indicating that UHS-3 has a faster transfer rate.

It should be noted that UHS-1 and UHS-3 can have a UHS bus type of UHS-i, UHS-ii, or UHS-iii.


When shopping for a new micro SD card, storage space is also an important factor to consider. U3 SD card has more storage space compared to U1.

The capacity of the U1 Micro SD card ranges from 16GB to 512GB. On the other hand, the U3 offers a capacity from a minimum size of 16 GB to a maximum size of 1 TB.

Therefore, due to the difference between the U1 and U3 specifications, U3 is more suitable for people who want to store large, hour-long video recordings.

class video speed

Video speed class is another important feature when comparing U3 to U1. On the front of the SD card, you'll see the letter "V" plus the Roman numeral, the symbol that stands for "Video Speed ​​Class."

U1 SD cards do not have the Video Speed ​​Class feature on top of the card. Therefore, it becomes difficult to identify the exact video speed class of this card.

The U3 SD card has the symbol "V" with the number 30 next to it at the top of the card. Therefore, the U3 Micro SD card offers more video recording options compared to the U1 model.

The V30 icon indicates that you can easily record 30 Mbps HD video without dropping a single frame. As of now, this feature is only available on SDXC cards.

Video Speed ​​Class was created to enable higher video resolution and recording capabilities, such as multiple video streams, 360-degree capture, virtual reality content, and 4K or 8K resolution video.

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There are five video speed class ratings:

V6 - Video Speed ​​​​​​Class 6 with a minimum write speed of 5 MB per second.

V10: Video Speed ​​Class 10 with a minimum write speed of 10MB per second.

V30: Video speed is 30 with a write speed of 30MB per second.

V60: Video speed is 60 with a write speed of 60MB per second.

V90: Video speed is 90 with a write speed of 90MB per second.

This feature is unique in that it can use the UHS-1 and UHS-2 bus interfaces.

Speed ​​class V6 to V90 memory cards can use the UHS-ii bus interface, while the UHS-i bus interface only supports speed class V6 to V30 memory cards.

Different speed rating for SD card or micro SD card

Within the speed class there are different classifications, which are marked with the symbol "C". The different classes that the memory card comes in are:

C2 - Class 2 with a minimum write speed of 2 MB per second.

C4 - Class 4 with a minimum write speed of 4 MB per second.

C6 - Class 6 with a minimum write speed of 6 MB per second.

C10 - Class 10 with a minimum write speed of 10MB per second.

C2 is the lowest speed rating, while C10 is the industry standard. Today newer hardware devices require newer speed classes with higher speeds and capacities.

C10 is typically the minimum speed rating for most hardware devices made today and is the most commonly shipped memory card on the market.

About SD card speed

A speed class is specified on the front of each SD card. These "classes" determine the speed of the memory card. SD card speed can read and write at speeds of 12.5MB by default.

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You need a faster memory card if you are shooting RAW or HD video. If you just want to store a few photos or documents, you don't need a faster memory card.

With the development of SD cards, the ultra high speed class is now available on many SDXC and SDHC micro SD cards.

A faster memory card supports larger files and processes them faster. So if you're shooting in 4K or RAW files, you'll need an equally powerful SD card to keep up with all those files.

How to choose an SD card

There are many types of SD cards: SD, SDHC, and SDXC. Since SD cards have been known to shrink in size in recent years, the "SD" card can be considered a "full size" card.

It is used in most modern digital cameras and almost all laptops come with an SD card reader slot fitted.

SDHC stands for Secure Digital High Capacity. This type was introduced to cover SD cards with capacities greater than 2 GB and less than 32 GB.

SDXC stands for "Secure Digital eXtra Capacity", which goes well beyond 32GB.

It's worth noting that all of these types of SD cards look the same, so they all fit into a regular SD card slot.

What you should be careful of is buying an SD card depending on the device you want to use it on and if they are compatible, otherwise problems may arise.


U3 Micro SD card is better than U1 card in transfer speed, video speed class and ultra high speed class. So between U1 or U3, U3 is the ideal choice for all users.

UHS I vs. Class 10 Cards

What is UHS U3?

UHS is the minimum sustained write performance for recording video, and for the u3 SD card it is three.

Is UHS 1 the same as Class 10?

Yes, UHS 1 is class 10 as they have the same minimum data transfer speed of 10 Mbps. The technical data is also identical.

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U3 is better than U1?

Yes, U3 is better than U1 as it has some features that the other model does not have. Therefore, it can perform more functions, making it a better choice.

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Shabbir has always loved photography. She's been a passion of his for 20 years and he's never looked back since he started with film SLRs. He currently prefers to use a Canon mirrorless camera and his current favorite is the EOS M50. He loves how versatile it is and how easy it is to transport.

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    Is a U3 better than a U1 for SD card? ›

    The first thing to consider between a U1 vs U3 MicroSD is the data transfer speed. Compared to the U1 Micro SD card, the U3 SD card has a faster data transfer speed. If you want to have a high write and transfer speed to record 4K Ultra-HD video, then the U3 SD card is the ideal choice.

    What is the difference between U1 and U3 speed on SD card? ›

    The next speed class up is the UHS (Ultra-High Speed) Speed Class and it's denoted with the “U” symbol. There are two ratings within the UHS Speed Class: U1 (UHS Speed Class 1): minimum write speed of 10MB/s. U3 (UHS Speed Class 3): minimum write speed of 30MB/s.

    Which is better UHS 1 or UHS 3? ›

    UHS Speed Class 1 supports a minimum 10MB/s write speed, whereas UHS Speed Class 3 supports at least 30MB/s write speed. The UHS Speed Class is denoted by either a 1 or 3 inside of a bucket U symbol. As a rule of thumb, 4K-capable camcorders will usually require at least a U3 rated SD card.

    Which are SD card types choose two answers? ›

    The two standards that are more popular today for both SD and microSD cards are SDHC and SDXC. The main difference among the SD standards is storage capacity. If you shoot 4K video, you'll most likely need an SDXC card since it has a maximum capacity of 2TB which is plenty for optimal video recording performance.

    Is U3 enough for 4K? ›

    SD cards have six different speed classes. Only the U3 class is capable of writing at the speed required for 4K video which is 30MB/s. Choose only cards that have the U3 marking (The number 3 inside a capital U).

    Is U1 fast enough for 4K? ›

    UHS Speed Class – SD cards

    This speed class is known for very rapid data transfer – up to 312 megabytes per second – from the SD card hardware to the device central processing unit (CPU), otherwise known as bus-interface speed. These classes include UHS 1 (U1) and UHS 3 (U3) and support full HD to 4K video formats.

    What speed SD card should I get? ›

    Class 2: a minimum write speed of 2MB/s. Class 4: a minimum write speed of 4MB/s. Class 6: a minimum write speed of 6MB/s. Class 10: a minimum write speed of 10MB/s.

    Which SD Speed is best? ›

    For ultra-fast SD cards, these are probably more relevant. UHS-I cards have a theoretical maximum of 104 MB/s, while UHS-II cards top out at 312 MB/s.

    Which type of SD card is fastest? ›

    The fastest Secure Digital (SD) memory card. The fastest SD memory cards currently available are UHS-II cards. The UHS-II interface is capable of up to 312MB/s bus speed while actual card transfer speeds are slightly lower. A total of 191 SD cards were tested using benchmark software in several card readers.

    Which microSD card is most reliable? ›

    The best microSD cards you can buy
    • Samsung Evo Plus microSD card. Best microSD card overall. ...
    • Lexar Professional 1066x microSDXC card. Best microSD card for video. ...
    • Samsung EVO Select microSD memory card. Best microSD card value. ...
    • SanDisk Extreme SSD V2. Best large-capacity microSD card. ...
    • SanDisk Extreme Pro MicroSDXC card.
    Feb 17, 2023

    Which SD card is best? ›

    • SanDisk 128GB Class 10 microSDXC Memory Card. ...
    • Samsung EVO Plus 64GB microSDHC Memory Card. ...
    • SanDisk 32GB Class 10 Micro SDHC Memory Card. ...
    • HP 64GB Class 10 MicroSD Memory Card. ...
    • Strontium Nitro A1 128GB Micro SDXC Memory Card. ...
    • SanDisk 64GB Extreme microSDXC Memory Card.
    Sep 6, 2022

    Do SD cards go bad? ›

    Overall Lifespan of SD Cards. There is no definite lifespan of an SD card, despite their theoretical 30-year timeline. Based on the current flash memory technology, most SD cards are projected to last ten or more years. However, cards that get heavy use are prone to wear out quicker.

    Does it matter what kind of SD card you use? ›

    The important factors in choosing a memory card are speed, capacity and the type of device you're using it in. Having the most capacity at an affordable price is ideal but it's also important to have a memory card that has a fast enough write speed to capture all your footage without any errors.

    Does the brand of SD card matter? ›

    Most genuine, brand-name microSD cards are fine most of the time, and there won't be a problem if you don't want to overthink making your choice. But for about the same price, some cards are a bit faster or offer a tad more reliability, which can make them more versatile and a better long-term value.

    What are the 4 types of SD cards? ›

    While they are all commonly known as SD cards, there are currently four sub-types of secure digital cards: SD, SDHC, SDXC, and SDUC.

    Is U3 louder than U1? ›

    The big sister to the U1, the Yamaha U3, at 52” tall and 59” wide, offers many of the same advantages to the U1, and more. The U3 provides a sound which is both louder and richer, thanks to its larger soundboard surface area and longer bass strings.

    Which class is best in SD card? ›

    On most modern SD cards, that number is 10, which is the highest classification for this class. Class 10 cards are capable of at least 10 megabytes (MB) per sec. Since most cards are capable of much, much faster speeds, this symbol is a bit outdated.

    Which class is best in microSD card? ›

    The SD Card Association recommends UHS Speed Class 3 (U3) or higher for shooting 4K video, and V60 or above for 8K video. For full HD video, it suggests Class 10 or a Class 6 microSD card under certain circumstances. If your card's write speed is too slow, it will drop frames and produce stuttering video.

    What is the best SD card rating? ›

    Best SD cards
    1. SanDisk Extreme PRO SDXC UHS-I. ...
    2. Lexar Professional Class 10 UHS-II 2000X. ...
    3. Kingston Canvas React Plus SDXC UHS-II. ...
    4. PNY X-Pro 90 SDXC UHS-II. ...
    5. SanDisk Extreme PRO SD UHS-II. ...
    6. SanDisk Extreme SD UHS-I Card. ...
    7. Lexar Professional 633x SDHC / SDXC UHS-I. ...
    8. Transcend SDXC UHS-II U3.
    Feb 16, 2023


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