Use Lexar CFexpress Type A Gold Series card. Based on reviews on the web, this is the best CFexpress Type A card.

I love Angelbird AV PRO CFexpress Type-A card. Very fast on my a7 IV.

I've been using the Sony a7 IV for a few months now, and I highly recommend the Sony Tough CFexpress Type-A cards. They offer fast read and write speeds which are perfect for high-resolution photos and 4K video. You won't experience any lag with these cards!

You can also try the UHS-II SD cards for a cheaper price range.

For the Sony a7 IV, prioritize UHS-II V90 SD cards for optimal speed and performance. While V60 is acceptable, V90 minimizes buffering, especially for video. Consider CFexpress Type A cards for even faster speeds, as the a7 IV has dual slots. Reliable brands are key for longevity. Choose a capacity that suits your shooting style and budget.

For optimal performance with your Sony a7 IV, consider using CFexpress Type A cards like the Sony TOUGH series, offering up to 800 MB/s read and 700 MB/s write speeds. Alternatively, UHS-II SD cards such as the SanDisk UHS-II V90 SD provide up to 300 MB/s read and 299 MB/s write speeds. Both options are reliable and cater to high-resolution photography and 4K video recording needs.

If you're looking for a more budget-friendly option, high-end UHS-II SD cards can still provide excellent performance, especially for still photography and lower-bitrate video.

CFexpress Type-A card is the best choice, Get brands such as Lexar, Sony.

OWC 960GB Atlas Pro High Performance Cfexpress 4.0 Type A Memory Card.

tbh i have been pretty disappointed with some of the big name brands lately. unfortunately, i spent a fortune on cards that promised the world but ended up overheating during long video shoots on my a7 IV. it's kinda annoying when you're mid-session and the camera starts lagging because the card cant handle the heat. honestly, most people focus too much on those peak burst speeds on the packaging, but they don't tell you about sustained write speeds. thats where the real performance actually happens. i ended up switching to ProGrade Digital SDXC UHS-II V90 Cobalt and its been a total lifesaver. the sustained speed is legit so i dont get those weird buffer hangs. if you're doing heavy video and want something that wont die on you, check out Delkin Devices BLACK CFexpress Type A too. they are rugged as heck and actually stay cool. dont just buy for the logo on the front, look at the thermal management and minimum sustained speed ratings instead... it makes a huge difference.

I bought the Lexar 160GB Professional CFexpress Type A SILVER card for a7IV, love it. No problems.