Yes, the Samsung PRO Plus 256GB SD is compatible with the Sony A7 IV.
Samsung PRO Plus is UHS-I V30. Sony A7 IV spec table requires V30 minimum for XAVC HS 4K (Long GOP modes) and V90 minimum for XAVC S-I 4K (Intra-frame). Card meets V30 for HS modes but fails V90 for S-I intra-frame recording.
Limitation
Cannot record XAVC S-I 4K (Intra-frame) -- requires Video Speed Class V90, this card is V30. Works for XAVC HS 4K (Long GOP) and all lower-bitrate modes; card runs at UHS-I speed in the UHS-II slot.
“Sony A7 IV Help Guide card table: XAVC HS 4K at 200Mbps requires SDHC/SDXC U3/V30 or higher; XAVC S-I 4K at 600Mbps requires SDXC V90 or higher — V30 UHS-I card supports standard 4K formats only.”
“UHS-I Speed Class 3 (U3) and Class 10 for 4K UHD and FHD video”
Last verified:
Confidence: inferred