Yes, the Lexar Professional 1667x 64GB SD is compatible with the Panasonic LUMIX GH7.
Panasonic LUMIX GH7's SD slot (Slot 2) accepts Lexar Professional 1667x 64GB SD directly. Lexar Professional 1667x 64GB SD is V60 class. Clears: Motion pictures (72 Mbps, requires V10); Motion pictures (200 Mbps, requires U3); Motion pictures (400 Mbps, requires V60). Does not meet the floor for: Motion pictures (600 Mbps, requires V90). No setting or firmware update changes a card's rated speed class. Also, above 600Mbps -- including variable frame rate with ALL-Intra and internal ProRes/ProRes RAW recording -- Panasonic's own spec states these require a CFexpress card; no SD card of any class can record them.
Limitation
Cannot record above 600Mbps on the SD slot (variable frame rate ALL-Intra, ProRes/ProRes RAW) regardless of card class -- CFexpress only. On top of that, this card's own class falls short of one or more of the lower Long-GOP tiers -- see the clause above for exactly which.
“Motion pictures with 72Mbps or less: CFexpress card, SD memory card with SD Speed Class with Class 10 or Video Speed Class 10 or higher Motion pictures with 200Mbps or less: CFexpress card, SD memory card with UHS-I / UHS-II UHS Speed Class 3 (U3) or Video Speed Class 30 or higher Motion pictures with 400Mbps or less: CFexpress card, SD memory card with Video Speed Class 60 or higher Motion pictures with 600Mbps or less: CFexpress card, SD memory card with Video Speed Class 90 Motion pictures with 800Mbps or more, variable frame rate with ALL-Intra, or ProRes: CFexpress card”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)