What's the difference between the Type B 4.0 Gold cards and Type B 4.0 Iridium cards?Updated a day ago

The main difference between the CFexpress 4.0 Type B Gold cards and CFexpress 4.0 Type B Iridium cards, is that the Iridium Type B 4.0cards offer higher performance and are VPG 400 certified. 

The Type B 4.0 Iridium cards have a read speed of 3550MB/s, write speed of 3000MB/s, and sustained write speed of 850MB/s (400GB) and 1500MB/s (800GB, 1.6TB) and are VPG 400 certified. The VPG 400 certification ensures that the minimum sustained write speed will not fall below 400MB/s. Some cinema cameras like the Sony Burano require a VPG 400 card. Cameras like the Canon R1 and R5 II recommend using a VPG 400 card. 

The Type B 4.0 Gold cards have a read speed of 3100MB/s (240GB) and 3400MB/s (512GB, 1TB, 2TB), write speed of 1600MB/s (240GB) and 3000MB/s (512GB, 1TB, 2TB), and sustained write speed of 700MB/s (240GB), 850MB/s (512GB) and 1500MB/s (1TB, 2TB). The Type B 4.0 Gold 1TB and 2TB are RED approved. 

Utilizing the CFexpress Type B Single-Slot USB 4.0 (PG05.6) reader in conjunction will enable you to get the transfer speeds that the Type B 4.0 cards offer. You will also need to ensure that your device is compatible with USB 4.0, Thunderbolt 4, or Thunderbolt 3.