Sandisk plans to launch first SD cards with around 900 MB/s speed in the summer

In addition to the presentation of Sandisk's first SDUC SD card with 4 TBs, the Western Digital subsidiary also presented two smaller but potentially very fast SD Express cards in the run-up to the NAB Show in Las Vegas.

There are two models: one bigger in SD format and the smaller one, in microSD format. Both cards have a capacity of either 128 or 256 GB. Thanks to the new SD Express interface, a leap in the speed will be quite significant, even if Sandisk only provides rough figures. Compared to Sandisk's own UHS-I cards, the SD Express models are said to be 4.4 times faster.

It should be noted here that Sandisk achieves higher data rates than the standard actually allows using UHS-I via proprietary methods. Sandisk achieves 200 MByte/s with a row of pins on the back of the card. However, this requires a special SD card reader.

The cards should, therefore, be able to achieve a peak of around 900 MByte/s. This is three times higher than Sandisk's previous maximum for UHS-II SD cards. It is not yet as fast as Sandisk's Cinema CFExpress cards, which achieve well over 1 GB/s. However, the SD Express standard still offers some room for improvement to enable faster speeds (see table below).

At least the image of the new SD card also provides precise data. The bigger SD card can read at 880 MB/s and write at a maximum of 650 MB/s via the SD Express interface.

The SD Express cards are compatible with old SD card readers, but then revert to UHS-I mode. It is still unclear whether the proprietary mode will be supported. UHS-II or even -III is not possible. Due to the standard, interested parties will have to consciously choose an interface in the future, and will not always be able to use the high speeds, even if the reader actually supports higher speeds.

The new SD Express cards are set to be launched on the market in the summer of 2024. Sandisk has not yet announced a price.

The SD Express standard has only made slow progress so far. Cards with the interface have already been seen here and there. AData, for example, showed an SD Express card at Computex 2023 in Taipei with a speed of 1.6 GB/s. However, there have been no major announcements to date.

It will be interesting to see if there is any movement in the SD card offerings in the context of the important industry trade fair NAB.