Earlier this week, Lexar announced a new SD 8.0 card that promised read speeds up to 1,700 MB/s and write speeds up to 1,000 MB/s, which is leaps and bounds faster than the all-metal SDXC cards it announced alongside them. As great as that sounds, this card is not fully compatible with anything and that speed will never be fully realized.
In what feels like a semi-annual refrain that we make here at PetaPixel, super-fast SD cards remain a practical myth. What’s weird this time is the branding shift to simply SD 8.0. This format is no different than SDexpress, a card type that has from the very outset been dead and unsupported.
What is SD 8.0?
SD 8.0 is no different from SD Express — it’s the same defunct card format that the SD Association announced in May 2020 just with the “express” part taken out. SD 8.0, SD Express 8.0, or SD Express all refer to the same card format.
This card can theoretically transfer data at speeds of up to 2 GB/s thanks to PCIe 4.0 due to an update the SD Association pushed to the specification last October. The key word there is “theoretical,” because not only have cards developed under the standard never reached that speed, but no real-world case of SD Express 8.0 has come close either.
Unlike how the Compact Flash Association (CFA) has approached the design of next-generation memory cards, the SD Association has not done more than take the next generation of the PCIe standard and announce a specification that supports it without doing anything more to assure that the standard can even be successful. That much should be obvious based on the widespread support for the CFA’s CFexpress format and the dead, nonexistent support for SD Express.
Back in 2019, PetaPixel spoke to ProGrade Digital’s Wes Brewer who explained the litany of problems with SD Express 8.0 and why it was always dead on arrival.
“The SD association tried to position the SD standard around the emerging PCIe interface adoption by especially the CF association,” he explained. “They came out and made a design that was compatible form-factor-wise with the SD card, but it only supports one lane of PCIe. They really just bolted a single lane of PCIe onto the form factor of an SD card.”
The pipe dream promise of SD Express has been backward compatibility, two words that immediately grab the attention of photographers. Unfortunately, it’s only technically backward compatible — not practically.
“It is only backward compatible to UHS-I in terms of the SD standard… You can put it in there, and it’ll work, but it’ll only work as a UHS-I card,” Brewer explained.
That fact has not changed and given that modern cameras have long outpaced the sluggish performance of UHS-I cards (they cap at 30 MB/s) — even in photography-specific applications and disregarding video entirely. Higher-resolution photos and faster burst rates have left UHS-I in the dust.
This, along with the fact that the CFexpress specification is more flexible, is why no camera manufacturer has signed on to use SD Express. Only a scant few computers come with built-in SD express card readers, but with nothing out there able to shoot to it at anywhere near the promised speeds, it’s a dead format. It was dead in 2019 and it is dead now.
This Card is Effectively Useless
All this said, for some reason, card makers keep announcing SD Express (or SD 8.0 now; apparently it needed a rebrand) even if they never actually make it to market. That’s right, Lexar already announced that it was developing SD Express cards in June 2021. Back then, it promised 800 MB/s transfer speeds that, while not as fast as this week’s promises, are still almost four times faster than the average UHS-II SD card.
That card never materialized — it never even got a product page on Lexar’s website. This isn’t really surprising, as even if it was available, it’s unclear who would buy it. It’s going to be a very expensive SD card that will only work as well as a cheap sub-$20 UHS-I SD card. It makes no logical sense. Google’s top-recommended SD Express card and reader that are actually available to purchase is basically a scam.
No photographer should let cardmakers sell them a myth. Lexar’s new SD 8.0 card is not compatible with any camera at full spec, will always be an overpriced UHS-I card, and probably won’t even make it to market.
For those of you who still hold hope for the widespread adoption that will meet the dream of SD Express, I’m sorry: it’s never happening. This specification is and always has been too broken and flawed to be adopted.