What does sdhc mean? What is the difference between sdxc SDUC and SD card (which is better, sdhc or sdxc)?

There are many kinds of memory cards in the market, and the price difference is huge. It's really hard to refuse to choose a memory card suitable for your own use. Today, two dog hopes that through the introduction of this article, we can better understand the memory card, and then choose the memory card products that suit us.

Introduction of common memory cards:

The memory card market has developed for many years. At present, the common memory cards on the market mainly include SD card and MicroSD card.

The former is 24mm x 32m x 2. 1mm, and the latter is15 mm x11mm. Due to the obvious difference in size between the two cards, SD card is generally called large card and TF card is called small card. Small cards can be converted into large cards through special adapters.

In addition to the common big cards and small cards, you can also see memory cards such as CF cards and QDA cards on the market. These memory cards are of little use, so I won't introduce them here.

Basic knowledge of memory card:

Memory cards are divided into large and small cards, capacity and speed.

1) Memory cards are classified by capacity:

SD: The earlier version has been basically discontinued now, with a maximum capacity of 2GB.

SDHC: This is a mature technology with a capacity of 4GB-32GB.

SDXC: At present, the mainstream memory card in the market has a capacity of 64GB-2TB.

SDUC: new version with a capacity of 2TB- 128TB.

2) Memory cards are classified by speed:

Grade standard:

The speed grade of early memory cards was determined by class grade, including C2, C4, C6 and C 10 specifications. The higher the level, the faster the transmission speed. At present, the fastest 10 level, referred to as C 10, is very common. The slower C6, C4 and C2 memory cards have been withdrawn from the market.

UHS grade standard:

UHS is a brand-new public transport mode, and there are three versions at present: UHS-I, UHS-II and UHS-III. The transmission speed of UHS standard needs equipment support, and the high version of backwards compatibility is the low version. If this standard is not supported, it can be used for ordinary memory cards with reduced speed. Use the daily U 1 and U3 levels to determine the minimum writing speed. The maximum reading speed of UHS-I card is 104M/S, that of UHS-II card is 3 12m/s and that of UHS-III card is 624m/s. 。

VSC grade standard:

VSC video speed levels include V6, V 10, V30, V60 and V90 specifications. After the demand for 4K video shooting increased, SD Association set a video speed level for video shooting applications, which used the identification letter V plus the number of the lowest writing speed value to form the logo. For example, the memory card for shooting 4K video must reach V30, and the slightly higher 4K video must reach V60.

PS: Memory card packaging will generally indicate the reading speed, and the grade standard is the minimum writing speed. Reading speed is generally faster than writing speed, please pay attention to the difference.

Application-level performance standards:

We often see A 1/A2 on many TF cards. What does this mean? When files are read and written continuously, it is easy to lose speed. The performance of application layer is to specify the minimum speed that can be maintained under the condition of speed loss caused by various factors. At present, there are only two grades A 1 and A2, and their minimum writing speed is 10M/S, but the requirements for minimum random reading speed and minimum random writing speed are different.

Memory card bus frequency:

In order to counter competing products such as QDA cards, SD Express standard is newly introduced, and the maximum speed of 985M/S greatly improves the performance of memory cards. The performance of the memory card under the new standard is really strong, but at present, UHS-I and UHS-I are the mainstream, which is enough for daily use. The new standard is of little significance to ordinary users.

3) Understand the standard icon parameters on the memory card:

With the above knowledge reserve, we can easily read the parameter content on the memory card. Take the above memory card as an example:

Brand and series: Sandisk Supreme PRO series

Reading speed: 170 m/s

Capacity category: SDXC memory card

Video speed level: V30, that is, the minimum writing speed is 30m/s.

UHS mode: supports UHS-I mode.

Class level: C 10, minimum writing speed10m/s.

Ultra-high speed level: U3, and the minimum writing speed is 30M/S when supporting UHS mode.

To put it simply, the above card is a 256G SD card, and the minimum writing speed is 10m/s in normal mode, 30M/S in UHS mode and 170m/s in maximum reading speed. ..

Memory card selection guide:

Just introduced the basic knowledge of memory card, so which size should I choose when buying? High-priced products can certainly meet the demand, but as ordinary users, they often need cost performance. Buying a memory card needs to be considered from four dimensions: capacity, brand, performance and warranty.

1) capacity selection:

According to our actual needs, determine the size of the memory card to be purchased. Generally speaking, we mainly consider two kinds of scenes: video shooting and photo shooting. Generally, mainstream 4K video shooting is selected, and the 128G card can easily shoot for nearly 3 hours, which can fully meet the needs of daily use. The static photo sheet is calculated as 30M, and the 128G memory card can store 4267 photos.

Considering the cost and particle price of the main control chip, the current mainstream SD card 64G/ 128G is very cost-effective. If you often need to shoot 4K video, it is recommended to buy 128G memory card. If it is mainly used for photo shooting, it is recommended to buy a 64G memory card.

2) Performance selection:

For memory cards, the most important specifications are reading speed and writing speed.

The picture above is an example. It is also a 128G Sony memory card, which has different reading and writing speeds, resulting in different prices.

In terms of speed, high-quality video is the kind that requires high performance of memory card in daily shooting. Aside from the special requirements, the reading speed of 200M/S and the writing speed of 90M/S can basically meet most requirements, and continuous shooting can handle 4K video shooting and high-quality photos. Of course, there is no shortage of money, and there are more professional needs. It is suggested that the 250M/S memory card can be read and written directly.

From the above picture, we can roughly understand the requirements of video standards for memory cards. Simply put, if you consider the future of the war or the budget is sufficient, you can directly use products with better performance. But considering the balance and cost performance, it is necessary to know the following information.

To record 1080P full HD video, it is recommended to select the memory cards marked with C 10, U3 and V30;

To record 4K ultra HD video, it is recommended to select the memory cards marked with C 10, U3 and V60.

PS: Some products with strong 4K performance require high speed because of their high bit rate. It is recommended to know the requirements of shooting equipment in advance before choosing such products.

If it is used in special scenes such as security, reading and writing speed is not the most important standard, but the stability, heat resistance and moisture resistance of the memory card are more important. Memory card products optimized in these aspects can be considered. For example, the Toshiba product in the above picture is optimized for the high temperature, low temperature and rain that may be faced in the security scene.

3) brand selection:

SD card is a relatively mature product, and there is little difference between products. Based on different positioning reasons, the product prices of brands, granules and main control chips are also different. Large manufacturers usually have better control over quality control and quality assurance. Choosing SD cards of big brands on the market is relatively more reassuring.

From my own experience, SanDisk, Sony, Toshiba and Samsung are all reliable brands. If you consider cost performance, you can also consider brands such as Lei Kesha and Kingston. Small brands with relatively low prices will not be recommended, and the price difference is not big, but the loss of valuable data caused by memory card damage will not be worth the loss.

4) Warranty and channel selection:

The warranty content varies with the nature of the memory card. The warranty period of ordinary memory cards of the same brand is 10 years, while the warranty period of special memory cards may only be 3 years. At the same time, the warranty time of agents and manufacturers is often different. Under the same conditions, it is recommended to choose products with longer warranty period.

There are a large number of fake cards and refurbished cards in the memory card industry, and the data is priceless. If you buy online, it is recommended to choose platforms such as JD.COM and Tmall.

Memory card knowledge question and answer:

Q: The storage space I want is 256G ... Should I choose a 256G card or two 128G cards?

A: It is generally recommended to choose two cards of 128G. There are two reasons. First, two 128G cards are generally cheaper than a 256G card. In fact, the most feared thing in shooting is data loss. Losing a 256G card data is everything. Two 128G cards can be * * * enjoyed.

Q: I mainly take pictures every day. Will the performance of TF card cover be worse than that of directly inserting SD?

Answer: The card holder only provides the golden finger switching circuit, which does not affect its speed transmission. When using the products produced by regular manufacturers, the speed of clamping sleeve that meets the conversion specification is not affected.

Q: How to choose the memory card of the driving recorder?

A: The memory card of the driving recorder does not require high speed, but it requires high stability and scene conditions. It is generally recommended to choose a memory card with long warranty period and optimized for high temperature and high humidity environment.

Q: Why can't my UHS- 1 memory card reach the nominal speed when copying data, and the values differ greatly?

Answer: The UHS- 1 memory card needs to cooperate with the card reader supporting UHS- 1 to achieve the corresponding transmission speed. If the data transmission of UHS 1 is not supported, the speed will be reduced. When purchasing a card reader, please pay attention to the supported transmission standards. Generally, only USB3.0 is an ordinary card reader, which is cheap but slow in transmission.

The price of the Sichuan-Chongqing card reader on the left is less than that of 20 yuan, with ordinary USB3.0 performance. The price of Sichuan-Chongqing card reader on the right is 59 yuan, USB3. 1 supports UHS-2. Obviously, the UHS-2 card needs to cooperate with the card reader supporting the corresponding standard to play a normal reading and writing performance. The specific choice of card reader depends on your own needs.

Q: What do the parameters similar to 633X on some brands of memory cards mean?

A: This is an early speed marking method, but it is rarely used by manufacturers at present. 1X= 150KB/S, how many times does x represent? For example, the speed of the memory card shown in the above figure is: 633x = 633 *150kb/s/1000 95m/s.

Q: How to distinguish between UHS- 1 and UHS-2 memory cards?

Method 1: directly look at the front identification part of the product and directly identify the type of memory card.

Method 2: check the golden finger of the product. If only one row of gold fingers is UHS- 1 memory card, there are two rows of memory cards on UHS-2.

Q: Which is more important, reading speed or writing speed?

A: General manufacturers will mark the speed on the card surface, where R stands for reading speed and W stands for writing speed. If there is only one speed, it is reading speed. Generally speaking, reading is faster than writing.

Generally speaking, when taking photos or high-quality videos continuously, the writing speed of the memory card is required to be high. When using game machines such as Switch, the reading speed of memory cards is often high. It is necessary to choose a reasonable memory card according to your own needs.

Recommended products:

Card reader product recommendation:

It is cheap and supports USB3.0. If the performance requirements are not low, you can consider this card reader.

For speed requirements, we can consider this Sichuan-Chongqing product, which supports UHS-2, and the price in 59 yuan is reasonable.

TF card product recommendation:

The orange card reads 100M/S and writes 90M/S, which can meet the requirements of 4K video shooting, audio and video storage and general photography.

Di speed card can read 160M/S and write 90m/s, and its excellent reading speed is suitable for gamers.

Toshiba has introduced a special memory card for driving records and safety requirements. The reading and writing parameters are not excellent, but they are optimized for the stability of specific scenes.

Read 100M/S, write 70M/S, and bring your own card sleeve. The price is relatively low, and it is suitable for use with expansion cards of switches and music players.

SD card product recommendation:

Sony high-end card, reading 300M/S, writing 299M/S, high-speed continuous shooting, 4K video shooting, reliable and durable. The only good thing is the high price, which high-end players can consider.

Sandisk's UHS-II memory card reads 300M/S and writes 260M/S, but the video level is not marked. Lifetime warranty is the highlight and the price is reasonable.

The positioning of E series is not high, but the speed of reading 270M/S and writing 120M/S should be enough for most shooting. Support V60 video level and IP57. If the stability requirements are high and the performance requirements are not harsh, you can consider this one.

The overall performance is similar to that of Sony E series, but the price is much cheaper. Read 250M/S and write 120M/S, supporting V60 video level. But pay attention to the version when buying. Lei Kesha 1667X series has a version with a writing speed of 90M/S, so pay attention to the distinction when purchasing.

Summary of main points of memory card purchase:

There is not much to say about dry goods in Tang Xian. If you don't want to read the full text, you can directly read the purchase point.

2) Daily shooting is mainly based on static photos, and both big cards and small cards have demand scenes. You can consider buying a combination of small card sets;

3)4K video shooting requirements, at least choose V30 standard memory card, and choose V60 or V90 memory card if possible;

4) When the budget is relatively sufficient, it is recommended to choose a memory card with a reading speed of 200M/S and a writing speed of 90M/S, which can meet various requirements such as 4K video shooting and still photo continuous shooting.

5) It is recommended to select a memory card with a capacity of 128G or above for video shooting, and a memory card with a capacity of 64G or above for non-video shooting;

6) Pay attention to distinguish the reading speed and writing speed of the memory card. Manufacturers usually mark the reading speed, but the writing speed of many memory cards is not ideal, and manufacturers often do not clearly mark the products.

7) High-speed cards need to be equipped with corresponding card readers, and good horses should be equipped with saddles, otherwise the performance of memory cards will be subject to the performance of card readers;

8) If the continuous reading and writing requirements are high, it is recommended to directly purchase A2-marked memory card products;

9) Stability is more important than speed in special card usage scenarios such as safety and driving records. This kind of scenario can give priority to optimized memory card products;

10) data is priceless. Try to choose high-quality memory cards within your affordability and try to buy them on a regular platform.

I hope everyone can choose a memory card that suits them, that's all. I have two dogs. See you next time.

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