Yes, the Lexar Professional 2000x 256GB SD is compatible with the Sony A7C II.
Lexar Professional 2000x 256GB SD is V90 class. Meets the floor for: 4K30 (30 MB/s floor); 4K60 (60 MB/s floor). (Peak write 260 MB/s is not evidence of sustained performance; the V90 class rating above decides this.)
“Sony A7C II Help Guide: XAVC S-I 4K at 600Mbps requires SDXC V90 or higher; XAVC HS 4K at 200Mbps requires SDHC/SDXC U3 or higher — V90 card meets all recording format requirements.”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)