====== One-for-All good article on cards ======

  * http://www.pentaxforums.com/articles/photo-articles/comprehensive-sd-card-guide.html


====== Card Type for Camera Storage======

  * most common type: SD card
  * high end sports camera: CF card
  * high end video camera: 2.5 inch SSD 
  * other cards: rarely used

====== SD card ======

**There are 3 size of SD card**
  * **Full size SD: most common type for cameras**
  * miniSD: rarely seen nowadays
  * microSD: most common type for slim compact cameras and smart phones
 
**We are mainly talking about Full size SD card From Here;**

**SD card has 3 property to consider when choosing**
  - capacity: how many GBs of storage
    * category label based on capacity:
      * SD: 1-2 GB
      * SDHC: 4-32 GB
      * SDXC: 64-128 GB and upto 2TB
  - Maximum Read/Writing speed: how fast it can quickly move in/out data
    * category label based on max R/W speed: (Mbps=mega bit per seconds, MBps = mega Byte per second = 8 Mbps)
    * normal lower uhs-i and lower cards use mbps (bit) to make number looks bigger, each gen speed also different
    * while higer uhs-i and uhs-ii card use MBps (Byte) as they are next gen card fast
      * R 280MB/s W 250MB/s : Video Pro
      * R 95MB/s W 90MB/s : Photo Pro
      * R 90MB/s W 60MB/s : Photo Burst Good
      * R 90MB/s W 40MB/s : Photo Burst Good
      * R 80MB/s          : Good
      * R 48MB/s          : Average
      * below             : Low
  - Example chart :
    * for 4K video, 100mbps, = 12.8MBps
    * for 4k video, 60mbps, = 7.5MBps
    * for FHD video, 28mbps, = 3.5MBps
    * so V30 card and 30MBps write is more than enough for common 4k video and below
    * while 60MP high res sensor burst shots will require far more write speed than video.

  * uhs-1 limit: 104MBps

^ name                          ^ video rate ^ Read ^ Write ^ price (2023) |
| SandDisk Extreme U3 UHS-I | V30 | 170MBps | 80MBps | 64GB = 13sgd |
| SandDisk Extreme U3 UHS-I | V30 | 180MBps | 90MBps | 128GB = 27sgd |
| SandDisk Extreme U3 UHS-I | V30 | 180MBps | 130MBps | 256GB = ?sgd |
| SandDisk Extreme Pro U3 UHS-I | V30 | 170MBps | 90MBps | 64GB = 15sgd |
| SandDisk Extreme Pro U3 UHS-I | V30 | 200MBps | 90MBps | 64GB = 18sgd-19.5 |
| SandDisk Extreme Pro U3 UHS-I | V30 | 200MBps | 90MBps | 128GB = 32sgd-35 |
| SandDisk Extreme Pro U3 UHS-I | V30 | 200MBps | 140MBps | 256GB = 55sgd-72 |
| SandDisk Extreme Pro U3 UHS-I | V30 | 200MBps | 140MBps | 512GB = 125sgd-139 |
^-^
^-^
| Sandisk Extreme Pro SDXC, UHS-II, 64GB | ? | 280MBps | 250MBps | 64GB |
| Sony E 64GB UHS-II | V30 | 270MBps | 70MBps | 64GB=25sgd |
| Sony E 128GB UHS-II | V60 | 270MBps | 100MBps | 128GB=60sgd |
| Sony M 64GB UHS-II | V60 | 277MBps | 150MBps | 64GB=35sgd |
| Sony M 128GB UHS-II | V60 | 277MBps | 150MBps | 128GB=92sgd |
| Sony M 64GB UHS-II Tough | V60 | 277MBps | 150MBps | 64GB=63sgd |
| Sony M 128GB UHS-II Tough | V60 | 277MBps | 150MBps | 128GB=99sgd |
| Sony G 64GB UHS-II Tough (for 8K) | V90 | 300MBps | 299MBps | 64GB=138sgd |
| Sony CFexpress 128GB tough | ? | 1700MBps | 1480 MBps | 128GB=306sgd |


  - Minimum video recording performance: how fast it can steadily record video
    * category label based on Minimum write speed (MB/s) and its corresponding Bus Mode (old to new):
      * Class 2,4 (2-4MB/s): Normal speed Bus (DVD resolution recording)
      * Class 6   (6MB/s  ): Normal speed Bus (HD-FHD resolution recording)
      * Class 10  (10MB/s ): High Speed Bus (High Quality HD-FHD resolution recording)
      * UHS 1     (10MB/s) : UHS-I Bus (High Quality HD-FHD resolution recording)
      * UHS 3     (30MB/s) : UHS-I/II Bus (4K resolution recording)
      * V30       (30MB/s) : UHS-I/II Bus (4K resolution recording)
      * V60       (60MB/s) : ? Bus (6K? resolution recording)
      * V90       (90MB/s) : ? Bus (8K? resolution recording)
    * category label based on its Bus Mode:
      * Normal Speed bus: 12.5MB/s
      * High Speed bus: 25 MB/s
      * UHS-I bus: 50MB/s - 100MB/s
      * UHS-II bus: 150MB/s - 300MB/s

  * ref:
    * camera support uhs-ii:
      * https://www.memorycard.expert/-Article/UHS-II-Cameras