Which memory card is best for your camera?

Memory cards come in several different shapes, sizes and speeds. Most cameras have only space for a type of card but on some professional cameras and camcorders  sometimes have room for two different cards. The card called SD (Secure digital) is by far the most common card in today's cameras but there are also MicroSD, CFexpress, XQD and CFast. Standard SD cards are used by compact cameras, system cameras and camcorders, among others. Depending on what a memory card is to be used for, different transfer speeds are required.

Still image photography with single images normally works with low memory cards transfer rate while today's 4K video recordings or if you are shooting multiple images in a burst sequence often require one fast and a large card with a high and stable transfer rate. To make it easy for the user to find the right memory card and for the purpose, there are certain signs and symbols on the card front page that tells you about the card's performance. In this guide, we go through all the symbols and types of cards so you can get the most out of your creativity!

SD (Secure Digital)

As mentioned the SD card is the most common memory card for all cameras. It comes in a variety of capacity and speed depending on what you need. Below we explain all the numbers and technical specifications so you get the right card for your camera.

1: Read speed
2: Capacity
3: Type of card
4: Video speed class
5: UHS Speed class
6: Speed class rating

1. 300 MB/s – Read speed
This is the maximum read speed of the card usually given in Megabytes per second (MB/s).

2000x
This is another (rather outdated) way of expressing the max read speed.The “x” identifier was originally adopted by Lexar and since implemented by many card brands in the industry. The higher the number before the “x” speed symbol, the higher the performance of the memory card. Each “x” represents 15MB/s. For example, you can figure out how fast a 1000x card is in KB/s by multiplying 150 by 1,000 and converting KB/s to MB/s by dividing by 1,000 (the answer is 150 MB/s). You could also just go by a card’s stated 300 MB/s speed.

2. 128 GB – Capacity
This is the card's capacity: SDHC cards range from 16GB to 32GB, and SDXC cards range from 64GB to 1TB.

3. SD XC – Type of card
This is the type of card; different card types use different file formats and newer cards won’t work in older card readers.

4. V.90 – Video speed class
A constant writing speed class for video recording. There are three kinds of Speed Classes, “UHS Speed Class” and “Video Speed Class.”This Speed Classes provide the constant speed necessary for video recording by designating a minimum writing performance, that includes V6, V10, V30, V60 and V90. V6 Speed Class means that the memory card performance needs to reach 6MB/s, V10 is 10MB/s and V30 is 30MB/s, and so on V60 and V90 can be applied to high resolution and high-quality 8K video recording, and V6, V10 and V30 can be applied to 4K resolution.SD maker will print these speed class symbols on the memory card (V60, V90…etc.). These speed class symbols will indicate to SDHC, SDXC UHS-I, UHS-I and SD memory card help users decide the best combination for reliable recording.

5. II, UHS – UHS Speed class
UHS stands for “Ultra High Speed” and refers to the technology that enables higher bus interface speeds on Secure DigitalHigh Capacity (SDHC) and Secure Digital Extended Capacity (SDXC) cards. Older UHS-I defines interface speeds up to 104MB/sec. An SDHC or SDXC card that supports “UHS” could have performance up to 104MB/sec. UHS-II is new generation UHS, UHS-II improve the interface speeds up to 312MB /s that

6. U3 – Speed class rating
Indicates how quickly video content can be transferred onto the memory card. UHS-I enables maximum transfer speeds of 104MB/s while UHS-II enables maximum transfer speeds of 312MB/s. Within the UHS Speed Class there are two designations, U1 andU3, which represent minimum write speeds of 10MB/s and 30MB/s respectively.

Class 10
Is an older speed-class rating. It is redundant of the UHS speed class, but many card manufacturers include it, as well, since many consumer products still recommend products based on the old standard. Class 10 is the fastest of the old speed class ratings and a class 10 card is verified to never write slower than 10 MB/s.

MicroSD

Micro SD is a quarter as large as a regular SD card and is the most widely used memory card in mobiles, GPS drones and action cameras. For today's 4K drones and action cameras, you need a fast and reliable card to ensure that you don´t miss anything.

1: Read speed
2: Application Performance Class
3: Video speed class
4: UHS Speed class
5: Card capacity 
6: Speed class rating

 

1. U3 – Read speed
Indicates how quickly video content can be transferred onto the memory card. UHS-I enables maximum transfer speeds of 104MB/s while UHS-II enables maximum transfer speeds of 312MB/s. Within the UHS Speed Class, there are two designations, U1 andU3, which represent minimum write speeds of 10MB/s and 30MB/s respectively.

Class 10 
Is an older speed-class rating. It is redundant of the UHS speed class, but many card manufacturers include it, as well, since many consumer products still recommend products based on the old standard. Class 10 is the fastest of the old speed class ratings and a class 10 card is verified to never write slower than 10 MB/s.

2. A2 – Application Performance Class
Application Performance Class - shows that the card is able to make apps more stable and improves the phone's performance.

3. V.30 – Video speed class
A constant writing speed class for video recording. There are three kinds of Speed Classes, “UHS Speed Class” and “Video Speed Class”. This Speed Classes provide the constant speed necessary for video recording by designating a minimum writing performance, that includes V6, V10, V30, V60 and V90. V6 Speed Class means that the memory card performance needs to reach 6MB/s, V10 is 10MB/s and V30 is 30MB/s, and so on. These speed class symbols will help users decide the best combination for reliable recording.

4. I, UHS – UHS Speed class
UHS stands for “Ultra High Speed” and refers to the technology that enables higher bus interface speeds on Micro Secure DigitalHigh Capacity (SDHC) and Micro Secure Digital Extended Capacity (SDXC) cards. Older UHS-I defines interface speeds up to 104MB/sec. An SDHC or SDXC card that supports “UHS” could have performance up to 104MB/sec. UHS-II is new generation UHS, UHS-II improve the interface speeds up to 312MB /s that

5. 256GB – Card capacity 
This is the card's capacity in GB.

6. 667x – Speed class rating
This is the cards maximum read speed. Each “x” represents 15MB/s. 

CFexpress

CFexpress cards are today the fastest memory cards out on the market. Professional cameras from Panasonic, Canon, Sony and Nikon are compatible with these memory cards. The card is a must if you want to take advantage of the latest camera features, including 8K video capture, in-camera uncompressed video recording and ultra-rapid burst modes.

1. Card read speed
2. Type of card
3. Card capacity 

1. 1750MB/s – Card read speed
Maximum read speed for the card. Write speed is 1000MB/s.

2. CFexpress Type B – Type of card
CFexpress comes in three different sizes (physical)Type A, B and C where A is the smallest and C is the largest. Today, most cameras that use CFexpress uses Type B but some newer models also start to use Type C.

Type A has one PCIe 3.0 pipeline, for a maximum 1GB/s speed, Type B has two pipelines, doubling to 2GB/s, and Type C has four pipelines for 4GB/s maximum data transfer rate.

3. 512GB – Card capacity

Note: the CFexpress card also works with some cameras that use XQD cards. XQD is a card t that was designed to be a successor to the CompactFlash card. It uses PCI Express as a data transfer interface. It is mainly used by older Nikon and Sony pro cameras.

Compact Flash

CompactFlash is one of the oldest flash memory formats and used to the professional photographer's number one choice thanks to it´s speed and reliable construction.

1: Card read speed
2: Minimum sustained write speed
3: Speed rating
4: Card capacity

1. 160MB/s – Card read speed
This is the maximum read speed of the card usually given in Megabytes per second (MB/s).

2. 65 – Minimum sustained write speed
This is the lowest speed the card will write. This speed (represented in MB/s) is important for videographers since sudden drops in writing speed can cause missed frames.

3. UDMA 7 – Speed rating
Stands for Ultra Direct Memory Access and is a system to more easily identify the transfer rates on the card. The number following the UDMA is typically between 0-7. UDMA 7 equals 167 MB/sec.

4. 256GB – Card capacity
This is the card capacity in gigabytes.

CFast

CFast is a fast and reliable card used by several pro cameras and camcorders like the Arri Alexa Mini and Canon C700. The CFast card looks almost identical to the CompactFlash card it’s based on, but it won’t fit in a CF slot, nor can it be read by a standard CompactFlash card reader.

1: Card read speed
2: Minimum sustained write speed
3: Speed rating
4: Card capacity

1. 525MB/s – Card read speed
This is the maximum read speed of the card usually given in Megabytes per second (MB/s).

2. 130 – Minimum sustained write speed
This is the lowest speed the card will write. This speed (represented in MB/s) is important for videographers since sudden drops in writing speed can cause missed frames.

3. CFast 2.0 – Speed rating
CFast 1.0 cards used the SATA 2.0 interface. The transfer speed of 1st generation Pretec CFast Storage Card is up to 160MB/s. The CFast 2.0 memory cards support SATA-3 interface, providing the continuous transfer speeds up to 600MB/sec. CFast 2.0 is suitable for high-end cameras and camcorders to record 4K videos.

4. 512GB – Card capacity
This is the card capacity in gigabytes.