iXM needs firmware 4.00.35 and IQ4 needs firmware 6.00.36 (Feature Update #8).



Write speed may be affected by several factors. Limits imposed by the card can be inherent limits or thermal throttling. Other limits may be software overhead or a limitation in the hardware interface. A newly formatted card used in optimal temperature will allow achieving its top speed.

Tested cards are:

  • Sony XQD 64Gb
  • Delkin Power 64GB (Firmware EDFM30.5 and up)
  • Delkin Power 128GB (Firmware EDFM30.5 and up)
  • ProGrade 128Gb
  • Wise 128Gb
  • SanDisk 128Gb
  • Wise 160Gb
  • Prograde 256Gb
  • Wise 320Gb
  • ProGrade 512Gb
  • Wise 512Gb
  • SanDisk 512Gb
  • Wise 640gb
  • Delkin Black 650Gb
  • ProGrade 1Tb
  • WD 1TB
  • WD 2Tb
  • Delkin Power 2Tb

Speed and and also sustainable speed may vary between cards.

In order to work with CFexpress the unit needs to be on a specific firmware level
iXM needs to be on firmware 4.00.35 or later. Download it here
IQ4 needs to be on firmware 6.00.36 (Feature update #8 or later) Download it here


Note: Other cards do work as well. Lesser quality cards are likely to have heat dispersion issues and variable transfer speed rate issues resulting in degrade in performance when shooting fast or card heating up.