Quick Answer

To get the best performance from your SanDisk Extreme PRO 128GB CFexpress Type B card, format it in-camera, run a speed test with a compatible reader, and avoid filling it past 90% capacity.

Why Speed Testing Matters for CFexpress Cards

CFexpress Type B cards like the SanDisk Extreme PRO deliver read speeds up to 1700MB/s and write speeds up to 1200MB/s, but actual performance depends on your camera model, card reader, and firmware. A speed test confirms you're getting the rated speeds and helps spot issues before a shoot.

Choosing the Right Card Reader

To achieve the advertised speeds, you need a USB 3.2 Gen 2×2 or Thunderbolt 3 card reader that supports CFexpress Type B. Using a slower reader will bottleneck performance and give misleading test results.

How to Speed Test & Set Up Your SanDisk Extreme PRO CFexpress Card

  1. 1. Format the Card In-Camera: Insert the card into your Fujifilm camera, go to the setup menu, and select 'Format'. This ensures the file system matches the camera's requirements and reduces the risk of write errors. Common mistake: formatting on a computer can create incompatible partitions. Always format in the camera you'll use.
  2. 2. Run a Speed Test with a Compatible Reader: Use a CFexpress Type B reader connected to a USB 3.2 Gen 2×2 or Thunderbolt port. Run a benchmark tool like Blackmagic Disk Speed Test or CrystalDiskMark to verify read/write speeds. If speeds are below 1000MB/s, check your reader and port. A USB 3.0 port will cap performance at around 500MB/s.
  3. 3. Set the Card Write-Protect Switch (If Present): Some SanDisk CFexpress cards include a physical write-protect switch. Ensure it's unlocked (not in the lock position) before shooting. This prevents accidental write protection. Common mistake: forgetting to unlock the switch after transferring files, leading to a 'card locked' error on the camera.
  4. 4. Manage Card Capacity for Sustained Performance: Avoid filling the card beyond 90% capacity. CFexpress cards can slow down when nearly full due to wear-leveling algorithms. Leave at least 10-15GB free for consistent write speeds. Checkpoint: after a heavy shooting session, offload files and format the card in-camera before the next use.
  5. 5. Verify Firmware Compatibility: Check your Fujifilm camera's firmware version against SanDisk's compatibility list. Some older firmware versions may not support the full speed of newer CFexpress cards. Update your camera firmware if needed. This is especially important for cameras released before 2023.

Product Facts