With a PCI ExpressCard 34 form factor and the industry-standard PCIe platform as its interface, capable of transfer rates of up to 8 Gb/s (1000 MB/s), the 128GB SxS-1 (G1C) memory card reaches a maximum read speed of 440 MB/s and a maximum write speed of 200 MB/s — twice the transfer rate of Sony's earlier G1A-series SxS cards. It's built for stable, reliable capture of high-frame-rate 4K video content on Sony's large-sensor 4K camera systems, giving content creators flexibility across 4K, 2K and HD acquisition and production. Wear-levelling and data-refreshing functions minimise data defects over the card's working life, and each card is put through a series of quality-assurance tests covering recording blocks, temperature cycles and operating environment.