Among photographic memory cards, what is the reading and writing speed considered to be a high-speed card? What are the criteria for choosing a memory card?

Among photography memory cards, what reading and writing speed is considered a "high-speed card"? What are the criteria for purchasing a memory card?

Let’s look at the first question first. What is the reading and writing speed of a SLR camera memory card to be considered a “high-speed card”?

First of all, memory cards are divided into CLASS2 CLASS4 CLASS6 CLASS10 and other specifications. Different levels correspond to different reading and writing speeds.

Class2 minimum 2MB/second and maximum 6MB/second

Class4 minimum 4MB/second and maximum 10MB/second

Class6 Minimum 6MB/sec Maximum 20MB/sec

Class10 Minimum 10MB/sec Maximum 48MB/sec

USH-I Minimum 45MB/sec Maximum 90MB/sec

Generally speaking, storage cards with a capacity of 2GB or more and a speed of CLASS2 or above are called high-speed cards.

However, in SLR photography, especially when high-end professional SLR cameras have very high reading and writing requirements, you generally have to choose a memory card with CLASS 10 or above.

Therefore, the criteria for purchasing a memory card are capacity, stability, and read and write speed.

Among photography memory cards, what is the reading and writing speed that is considered a high-speed card? What are the criteria for choosing a memory card?

What is the reading and writing speed of a high-speed card? Let’s first talk about how to distinguish between high-speed and low-speed cards.

There are two main issues with speed levels. The first is the Class level issue. Different levels can meet different application requirements: Class 0: Including conditions lower than Class 2 and not marked with Speed ??Class;

Class 2: Suitable for watching ordinary MPEG4 MPEG2 movies, SDTV, and digital camera shooting ;

Class 4: Can smoothly play high-definition television (HDTV), continuous shooting of digital cameras and other needs;

Class 6: Meet the requirements of continuous shooting of SLR cameras and the use of professional equipment; < /p>

class 10: To meet the storage needs of higher speed requirements.

The minimum reading speeds of memory cards of different speed levels are also different. For example, the minimum speed standard for Class10 products is 20MB/s. If you buy a Class10 product and test it with a card reader on your computer and the speed score does not reach 20MB/s under the professional software test, it means you have purchased it. It's fake, this is an unsafe and healthy product. In addition, UHS-1 is also a speed grade issue that needs to be understood. UHS-1 is just a high-speed transmission protocol interface. It is a new bus mode. UHS is Ultra Hight Speed. The maximum interface bandwidth can reach 104MB/s, while the previous conventional bus mode can only reach a maximum of 25MB/s. UHS-1 is backward compatible with existing bus interfaces. Devices that do not support UHS-1 can be used but cannot achieve the fastest speed. On the memory card, the product with the "I" mark indicates that this is a card using the UHS-1 interface, which has no direct relationship with speed. Only UHS-I memory cards marked with the "U1" mark can guarantee a writing speed of at least 10MB/s. Without this mark, the reading speed may be faster, but the writing speed may only be Class6 or even Class 4.

It is better to care about this than to care about the maximum read and write speed supported by the camera card slot, and the maximum capacity of the card supported, and then refer to these two indicators to buy a card. I see other people being verbose. I wrote a lot, and most of them were copied and pasted from Du Niang. I didn’t explain clearly why it is considered a high speed if it exceeds the limit. I don’t think there is a unified standard. It counts as a high speed card today, but not tomorrow. You can’t keep up. Yes, even if you buy the highest speed card, it will be in vain if the camera card slot does not have high read and write speeds. However, camera manufacturers are not good at it. Generally, they do not indicate how high the speed the card slot supports. In this way, some memory card manufacturers You can sign up for high-speed cards at will and earn higher profits! This means that even though you buy a high-speed card, high-speed continuous shooting still relies on the internal cache. Once the cache is full, the continuous shooting speed will immediately drop. Therefore, instead of paying too much attention to speed when buying a card, it is better to focus on compatibility and stability. Sex is more affordable.

Let me tell you my views on this issue:

The memory card mentioned in the question should be an accessory device of photographic equipment. It is incorrect to simply pursue reading and writing speed.

Different photographic equipment has different requirements. For early equipment, if you install the highest speed card today, it is possible that it does not support it yet.

On the other hand, if you take an old card that is older than the device, the device may not support it.

Take a camera and a camcorder in my hand as an example. Its product manual has clear requirements.

I think there are three main issues that should be considered. The first thing to do is to choose according to the required support range of the device's instruction manual. Second, choose a pair of brands. Third, consider the cost-effectiveness.

The description of the camera states that it should be level 6 or above, so you can choose level 6 or level 8. Just meet the requirements.

If the camera requires two levels, then it is enough to choose two levels and level 4 to meet the requirements. For example, my camera can only support 32G storage capacity. You choose higher speeds and larger capacity, but you are just spending money in vain. The device does not support it.

For reference only.

Class is a memory card transmission standard, class10, which represents a writing speed of 10mb per second and is marked as 10mb/s.

As the pixels of digital cameras become higher and higher, the mainstream has reached 20 million pixels, and the highest reaches 50 million pixels. If you use RAW format, each photo has 60-70mb, and the amount of data to be processed is increasing. The larger the card, the original speed can no longer meet the reading and writing requirements. UHS is a new transmission standard for memory cards. It is similar to the traditional class classification. However, UHS speed is much higher than class. It is divided into 3 levels, U3 is the most Advanced, writing speed can reach 200mb/s, and can shoot 4K video.

At present, most camera memory cards are relatively entry-level and low-end products, that is, they use low-end 3D NAND QLC flash memory particles and the lowest-end simple disk control. How much practical significance does this blind emphasis on initial reading and writing speed have? As time goes by, its speed drops obviously...

Suitable for 4k video recording at least 1000x. Flash memory must at least use MLC or TLC particles. You get what you pay for...

Very detailed, I have collected it. If you don’t understand, just buy SD card C6 and TF card C6.

Let’s look at the first question first. What is the reading and writing speed of a SLR camera memory card to be considered a “high-speed card”?

First of all, memory cards are divided into CLASS2 CLASS4 CLASS6 CLASS10 and other specifications. Different levels correspond to different reading and writing speeds.

Class2 minimum 2MB/second and maximum 6MB/second

Class4 minimum 4MB/second and maximum 10MB/second

Class6 minimum 6MB/second and maximum 20MB/second

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Class10 minimum 10MB/second and maximum 48MB/second

USH-I minimum 45MB/second and maximum 90MB/second

Generally speaking, the capacity is more than 2GB and the speed is CLASS2 or more. Cards with different levels are called high-speed cards.

However, in SLR photography, especially when high-end professional SLR cameras have very high reading and writing requirements, you generally have to choose a memory card with CLASS 10 or above.

Therefore, the criteria for purchasing a memory card are capacity, stability, and read and write speed.

What speed is considered high? In fact, it mainly depends on your actual needs. Don't blindly pursue the so-called nominal speed. That has no practical meaning. Excessively high storage speed will inevitably bring about excessive economic costs. In fact, it is not necessary.

The key is to have a fast writing speed. I only mark SDs with a writing speed of more than 100M per second.