How fast is your micro sd card? Learn all about data transfer speed

Are you looking for a micro SD card that allows you to transfer data quickly and efficiently? The speed of micro SD cards is crucial for users of cameras, smartphones and other electronic devices. In this article, we will tell you everything you need to know about micro SD speed and why you should invest in a high-speed one. Don't miss this opportunity to optimize the performance of your devices!

Main factors that affect the speed of microSD cards

MicroSD Card Speed ​​Classes and Standards

MicroSD cards are classified into different speed categories that determine their performance in terms of read and write speed. Understanding these classes and standards is essential to choosing the right microSD card based on the user's needs. The main speed classes and their associated read and write speeds are detailed below:

a) SD Speed ​​Class : SD Speed ​​Class microSD cards are the oldest and offer basic data transfer speeds. These cards typically have a minimum sustained write speed of 2 MB/s and are primarily used in older devices or in applications that do not require high transfer speeds.

b) SDHC Speed ​​Class : microSDHC (Secure Digital High Capacity) cards are an evolution of SD cards and offer larger storage capacities. These cards have a minimum sustained write speed of 4 MB/s and are suitable for devices that require higher performance, such as digital cameras and video recorders.

c) SDXC Speed ​​Class : microSDXC (Secure Digital eXtended Capacity) cards are high-capacity cards that can store large amounts of data. These cards have a minimum sustained write speed of 10 MB/s and are ideal for devices that record high definition (HD) and 4K video, as well as applications that require fast data transfer .

d) UHS (Ultra High Speed) : The UHS standard classifies microSD cards into two categories: UHS-I and UHS-II.

• UHS-I: UHS-I microSD cards offer faster transfer speeds compared to previous classes. They have a minimum sustained write speed of 10 MB/s and are suitable for devices that require high read and write speeds, such as professional DSLRs and camcorders.
• UHS-II: UHS-II microSD cards are the latest generation of cards and offer even higher speeds than UHS-I. These cards have a minimum sustained write speed of 30 MB/s and are ideal for applications that demand exceptional performance, such as 4K video recording at high bit rates.

It is important to note that the transfer speed mentioned for each speed class represents the minimum guaranteed speed. Some microSD cards in each class can achieve much higher read and write speeds, which depends on factors such as the quality of the card, the memory technology used, and the capacity of the device using it.

Transfer speed and nominal speed

Transfer speed and nominal speed are two important concepts to understand the performance of microSD cards. The difference between them and how the transfer speed is measured on these cards is explained below:

1. Difference between transfer speed and nominal speed:

• Transfer Speed : Refers to the actual speed at which data can be transferred to and from the microSD card. It is the most accurate and relevant measure to evaluate card performance. Transfer speed is generally expressed in megabytes per second (MB/s) and provides information about how quickly data can be read and written to the card. Higher transfer speed means faster data transfer .
• Rated Speed : Refers to the speed rating assigned to a microSD card based on its speed class (such as SD, SDHC, SDXC, and UHS). It is the minimum guaranteed speed that the card can maintain on a sustained basis. For example, a Class 10 microSD card has a minimum rated sustained write speed of 10 MB/s. However, it is important to note that the rated speed does not represent the maximum speed the card can achieve, but rather a guaranteed minimum.

2. How transfer speed is measured on microSD cards:

Transfer speed on microSD cards is measured through standardized tests using specialized programs and tools. These tests generate data that indicates the read and write speeds that can be expected from the card under ideal conditions.

Transfer speed tests are performed using specific blocks of data and measuring the time it takes for the card to read or write those blocks . The results are expressed in terms of transfer speed in MB/s. Some popular tools and programs used to measure the transfer speed of microSD cards include CrystalDiskMark, ATTO Disk Benchmark, and Blackmagic Disk Speed ​​Test.

It is important to note that transfer speeds may vary depending on several factors , such as the quality of the card, the interface used (SD, SDHC, SDXC, UHS), memory technology and the capabilities of the device on which the card is used. Additionally, transfer speeds advertised by manufacturers often represent the theoretical maximum performance of the card and may not reflect actual speeds achieved under real-world conditions of use.

We recommend you read this Guide on Types of Micro SD Cards

Technical aspects of speed on microSD cards

Types of interfaces used on microSD cards

MicroSD cards use different interfaces to establish connection and transfer data with devices. The most common types of interfaces on microSD cards and their characteristics and differences are described below:

• a) SD (Secure Digital): It is the original interface used in the first microSD cards. Offers slower transfer speeds compared to newer interfaces. SD cards have a maximum capacity of 2 GB and are not that common in today's market.
• b) SDHC (Secure Digital High Capacity): This interface is an evolution of the SD interface and allows larger storage capacities. SDHC cards can have capacities up to 32 GB and use the FAT32 file system.
• c) SDXC (Secure Digital eXtended Capacity): It is an interface that allows storage capacities even greater than SDHC cards. SDXC cards can have capacities up to 2TB and use the exFAT file system.
• d) UHS-I (Ultra High Speed) : This interface offers faster transfer speeds compared to SD interfaces. It uses a single-line data bus and can achieve read and write speeds of up to 104 MB/s.
• e) UHS-II (Ultra High Speed ​​II): It is a more advanced interface than UHS-I and offers even higher speeds. It uses a two-line data bus for greater transfer capacity. UHS-II cards can reach read and write speeds of up to 312 MB/s.
• f) UHS-III (Ultra High Speed ​​III): This is the latest interface and offers even faster speeds than UHS-II. It uses a four-line data bus for superior performance. UHS-III cards can reach read and write speeds of up to 624 MB/s.

It is important to note that the transfer speed of microSD cards depends not only on the interface used, but also on other factors such as speed class and memory technology.

Memory technologies used in microSD cards

microSD cards use different memory technologies to store data. The most common memory technologies and their advantages and disadvantages are described below:

• a) SLC (Single-Level Cell) : It is the oldest and most reliable memory technology. It stores a single bit of data per cell and offers high performance and durability. SLC cards are more expensive and have a lower storage capacity compared to other technologies.
• b) MLC (Multi-Level Cell) : Stores several bits of data per cell and offers higher storage density compared to SLC. MLC cards are cheaper and have higher storage capacity , but may be less durable and have slightly lower performance.
• c) TLC (Triple-Level Cell): Stores three bits of data per cell and offers higher storage density compared to MLC. TLC cards are cheaper and have even greater storage capacity, but can have slower performance and shorter lifespan.
• d) QLC (Quad-Level Cell) : Stores four bits of data per cell and offers the highest storage density. QLC cards are the cheapest and have the highest storage capacity, but their performance is slower and their lifespan is shorter compared to previous technologies.

Impact of memory technology on microSD card speed

The memory technology used in a microSD card can affect its transfer speed. In general, cards with SLC technology tend to offer faster performance and longer durability, while cards with QLC technology tend to have slower performance and shorter lifespan.

However, it is important to note that other factors, such as the interface used and speed class, also influence the transfer speed of microSD cards. For example, a microSD card with a UHS-II interface and a high speed class will perform faster regardless of the memory technology used.

Speed ​​and performance rating on microSD cards

Sequential read and write speed

Sequential read and write speed is an important aspect to consider when evaluating the performance of microSD cards. Here's what sequential velocity means and why it's important in different use cases:

a) Explanation of sequential reading and writing speed:

• Sequential write speed: Refers to the speed at which data can be written consecutively to the microSD card. In other words, it is the speed at which data can be transferred in a continuous, sequential stream. It is measured in megabytes per second (MB/s) and the higher the sequential write speed, the faster you can save large files or make high-quality video recordings.
• Sequential read speed: Refers to the speed at which data can be read consecutively from the microSD card. It is the speed at which stored data can be accessed in a continuous, sequential stream. Like sequential write speed, it is measured in megabytes per second (MB/s). Higher sequential read speed enables smooth playback of large media files and faster loading of applications and files.

b) Importance of sequential speed in different use cases:

Sequential speed is especially relevant in the following use cases:

• High-resolution photography and video: Capturing images in RAW format or recording videos in high resolutions, such as 4K or even 8K, results in large file sizes. A high sequential write speed is essential to ensure that the microSD card can quickly save data without delays, avoiding interruptions in image capture or video recording.
• Media Playback: When playing large media files, such as high-definition movies, a high sequential read speed is essential to ensure smooth and interruption-free playback. If the sequential read speed is too low, there may be pauses or stutters during playback.
• Large File Transfer : When copying or transferring large files to or from the microSD card, a high sequential read and write speed allows for faster, more efficient transfer. This is especially important when moving large amounts of data, such as video files, high-resolution images, or game files.

Random write and read speed:

In addition to sequential speed, there is also random read and write speed . These speeds refer to the microSD card's ability to handle multiple data read and write operations simultaneously or across dispersed storage locations. Unlike sequential speed, random speed is measured in input/output operations per second (IOPS).

Random read and write speed is important in use cases where fast, efficient access to smaller files is required or when multiple read and write operations are performed simultaneously. This may include tasks such as running applications, uploading small files, or managing multiple tasks on mobile devices.

Random speed can influence the overall performance of microSD cards as it affects the responsiveness and fluidity of everyday operations on the device.

Additional factors to consider when evaluating the speed of microSD cards

Video and photo recording speed support

When evaluating the speed of microSD cards , it is important to consider their compatibility with video and photo recording speed. This means taking into account the speed requirements for recording HD and 4K video, as well as recommendations for photographers and videographers regarding the speed of microSD cards.

Speed ​​requirements for high definition (HD) and 4K video recording:

High Definition (HD) and 4K video recording requires a sustained and constant write speed to ensure data is saved smoothly and without interruptions. Camera and device manufacturers often set minimum speed requirements for the microSD cards used in their devices.

For HD video recording , a sequential write speed of at least 10 MB/s is generally recommended. However, for 4K video recording, the speed requirements increase significantly. For standard 4K videos, a sequential write speed of at least 30 MB/s is generally recommended. For high bitrate 4K videos (for example, on professional cameras), even higher speeds may be required, such as 60 MB/s or even 90 MB/s.

It is important to check the camera or device manufacturer's recommended minimum write speed specifications when selecting a microSD card for HD or 4K video recording. This will ensure an optimal recording experience and prevent issues such as dropped frames or recording interruption due to inadequate microSD card speed.

Recommendations for photographers and videographers regarding the speed of microSD cards:

For photographers and videographers , it is advisable to use microSD cards with higher sequential write speeds to ensure optimal performance in image and video capture. In addition to meeting the minimum speed requirements established by the camera manufacturer, it is also suggested to consider the following recommendations:

• Higher Sequential Write Speed : Opting for microSD cards with higher sequential write speeds than the minimum recommended requirements can provide additional performance headroom and ensure smoother video recording, especially when capturing fast-action or high-speed action scenes. bits.
• UHS Speed ​​Rating : UHS (Ultra High Speed) rated microSD cards offer faster data transfer speeds compared to standard cards. UHS-I cards have a theoretical maximum speed of 104 MB/s, while UHS-II cards can reach speeds of up to 312 MB/s. If your camera or device supports UHS-II, opting for a UHS-II card can provide even faster performance.
• Speed ​​class and video rating : Some microSD cards are labeled with a speed class (such as Class 10, UHS Class 3) and a video rating (such as V30, V60, V90). These ratings indicate the minimum guaranteed sustained write speed for video recording. For 4K video recording, it is recommended to use cards with a video rating of V30 or higher, which guarantee a minimum sequential write speed of 30 MB/s.

App usage and performance on mobile devices

MicroSD card speed can also influence the overall performance of apps and games on mobile devices. Here are some considerations when selecting a fast microSD card for mobile devices:

• Loading and running applications : A microSD card with a high sequential read speed will allow for faster loading of applications from the card and smoother running, especially in applications that require accessing data stored on the card during operation.
• Gaming Performance : Some mobile games require fast loading of textures and game data. A microSD card with a high sequential read speed can improve gaming performance by speeding up the loading of this data, resulting in a smoother, stutter-free gaming experience.

When selecting a microSD card for mobile devices, it is advisable to opt for those with higher sequential read and write speeds, preferably with UHS speed ratings and video ratings suitable for high definition (HD) or 4K video recording.

Related questions

What is the minimum recommended speed to record video on a micro SD card to avoid interruptions or loss of quality?

To avoid interruptions or loss of quality when recording video on a micro SD card, a minimum speed of class 10 or UHS (Ultra High Speed) class 1 is recommended. This means that the card can handle a write speed of at least 10 megabytes per second, which is enough to record high definition videos without problems. Some more advanced cameras and devices may require even higher speeds, such as UHS class 3 or V30, depending on the resolution and bitrate of the video. It is important to note that using a card with a lower speed than recommended can cause compatibility and quality problems when recording video.

What is the difference between the read and write speed of a micro SD card and how does it influence the performance of my device?

Read and write speed is a measure of how quickly a micro SD card can transfer data . Read speed refers to the speed at which data can be read from the card, while write speed refers to the speed at which data can be written to the card.

The difference between read and write speed is important as it can significantly affect the performance of your device . If you're using a slow micro SD card, you may experience long wait times when opening apps, moving files, and taking photos or recording videos.

For optimal performance, it is recommended to use micro SD cards with high read and write speeds. Speeds are usually indicated in "Mb/s" or megabytes per second. High speed micro SD cards are generally classified into three categories: Class 10, UHS (Ultra High Speed) and A (App Performance Class).

Class 10 micro SD cards have a minimum read and write speed of 10 Mb/s, while UHS cards have much higher speeds, from 30 to over 600 Mb/s. Finally, A cards offer improved performance for high-demand applications and games.

What does the UHS speed rating mean on a micro SD card and how does it benefit me when using it on my smartphone or camera?

UHS stands for Ultra High Speed ​​and refers to the speed rating of a micro SD card. There are two types, UHS-I and UHS-II, the latter being faster. A card with a UHS rating can offer faster read and write speeds compared to conventional micro SD cards.

This benefits us when using it on our smartphone or camera, since our applications and processes for recording and storing large and numerous files run more efficiently and without interruptions. Additionally, it is especially useful for professional videographers and photographers who need to capture high-quality images at a high frame rate. In short, a UHS-rated micro SD card offers a faster and smoother experience in handling and storing data on compatible devices.

In conclusion, the speed of micro SD cards is a crucial factor when choosing the right one for our needs. Fast reading and writing of data is important for those who use their cards to store large amounts of information frequently. Classes and UHS are important in identifying card speed, while well-known brands like Sandisk and Samsung offer guarantees of expected quality and speed . It is important to take into account the use that we will give to our micro SD card to choose the one that best suits our needs. Don't underestimate the importance of speed!