Sony's A7S III mirrorless rumored to support new, cheaper, CFexpress cards

Sony A7S III rumors
(Image credit: Sony)

After years of waiting, we'll finally get to see the video-centric Sony Alpha A7S III on July 28, but in the meantime, rumors about the camera's features are running rife – including the notion that it could be the first ever camera to support CFexpress Type A cards.

The upcoming A7S III is rumored to feature dual card slots, and according to Sony Alpha Rumors – a reliable online news source on Sony's cameras – the new snapper will not only support CFexpress Type A cards but will also be able to use standard SD cards in either slot. 

While this is theoretically possible, there's one caveat – CFexpress Type A cards aren't available to buy at the moment and we have no idea how much they'll cost when they do appear on the market.

Express it differently

CFexpress cards themselves aren't new – they've been available for a while now, albeit with hefty price tags. There's support for this format in high-end professional cameras like the Canon EOS-1D X Mark III and the new Canon EOS R5, and support was added for it via firmware for the Nikon Z7 and Z6 mirrorless snappers.

But what most users don't know is that there are three different types of CFexpress cards – Type A, Type B and Type C – with the middle option currently in use and available to buy.

While all three types are based around the CFexpress 2.0 specifications and use the same superfast PCIe 3.0 and NVMe 1.3 technology, they differ in physical dimensions and in the number of data transfer lanes available in each.

CFexpress Type A is the smallest – measuring 28mm x 20mm x 2.1mm and similar in size to the standard UHS-II SD cards with dimensions of 32mm x 24mm x 2.1mm. In terms of speed, Type A only offers a single PCIe lane for 1GB/s data transfer speeds.

On the other hand, Type B cards are larger (38.5mm x 29.8mm x 3.8mm) and feature two 1GB/s lanes for max transfer speeds of 2,000MB/s. Type C CFexpress cards, which aren't yet available to buy either, are the largest of them (54mm x 74mm x 4.8mm), have four PCIe 3.0 lanes for a top speed of up to 4GB/s, and have been touted for use in computers as an alternative to solid-state drives (SSDs).

Good decision?

As the only ones currently available to buy, CFexpress Type B cards are quite expensive, but considering Type A cards will be smaller and slower, it's highly likely that they will be cheaper once they're arrive on the market. 

When that will be is unclear, but Sony has already confirmed a major launch event for later this month, so we could start seeing an influx of Type A cards into the market if this rumor is true. 

Sony is one of the biggest manufacturers of CFexpress and XQD cards, so there's a good chance the company will be ready to unveil a new storage format as well. It's also worth noting that the inclusion of dual slots compatible with two types of memory cards gives the upcoming camera a wider appeal.

We'll just have to wait a little longer to find out how this pans out.

Sharmishta Sarkar
Managing Editor (APAC)

Sharmishta is TechRadar's APAC Managing Editor and loves all things photography, something she discovered while chasing monkeys in the wilds of India (she studied to be a primatologist but has since left monkey business behind). While she's happiest with a camera in her hand, she's also an avid reader and has become a passionate proponent of ereaders, having appeared on Singaporean radio to talk about the convenience of these underrated devices. When she's not testing camera kits or the latest in e-paper tablets, she's discovering the joys and foibles of smart home gizmos. She's also the Australian Managing Editor of Digital Camera World and, if that wasn't enough, she contributes to T3 and Tom's Guide, while also working on two of Future's photography print magazines Down Under.