Transcend has unveiled a new series of microSD memory cards that support pseudo-SLC caching to boost burst write speeds. The new USD230I memory cards offer data transfer speeds of up to 100 MB/s as well as random read/write performance of up to 3,400 IOPS.

Transcend’s USD230I lineup includes microSD cards featuring 8 GB, 16 GB, 32 GB, and 64 GB capacities. The cards carry the A1 as well as the V30 badges, so they can be used to install Google Android applications and guarantee a minimum write speed of up to 30 MB/s, which is good enough for 4K video shooting.

Pseudo-SLC caching was introduced into the standard by the SD Association back in early 2017, but so far no actual memory cards have used this technology. Meanwhile, since Transcend’s USD230I use 3D TLC NAND memory, the only way to boost their writing performance is indeed through pSLC caching. Unfortunately, the manufacturer does not specify the sizes of its pSLC cache.

As far as endurance is concerned, the 8 GB model is rated for 36 terabytes to be written (TBW), the 16 GB/32 GB models are speced for 70 TBW, whereas the 64 GB variant is rated for 140 TBW.

Related Reading:

Source: TechPowerUp

Comments Locked


View All Comments

  • Guspaz - Tuesday, March 31, 2020 - link

    On the high end, ProRes 4444 XQ requires 4242 Mbps for 4K60. Raw formats go much higher. At some point, though, recording transitions to SSDs instead of SD cards.
  • ashleysguy43 - Sunday, April 5, 2020 - link

    Sara Jackson Makes $140 to $180 per day online work and i received $16894 in one month online acting from home.I am a daily student and work simply one to a pair of hours in my spare time.Everybody will do that job and monline akes extra cash by simply open this link... W­­W­W.iⅭ­a­s­h­68­.Ⅽ­O­Ⅿ
  • LiKenun - Monday, March 30, 2020 - link

    The industrial SD cards which use true SLC flash are horrible in terms of performance and capacity. Since this product has regular MLC backing the small pseudo-SLC bits, why is 64 GB the best that they could do? Delkin Devices has a V90 (90 MB/s minimum) MicroSDXC card that can do bursts of 250 MB/s write—though of course they do not claim to have the endurance afforded by SLC flash.
  • Santoval - Monday, March 30, 2020 - link

    The only way the small size could be explained is if the entirety of the NAND was in "SLC mode", which I highly doubt. The quite low minimum and maximum transfer/write speeds cannot be explained either way though.
    Industrial SD cards apparently have crappy controllers that cannot take advantage of their SLC flash. In their market the primary objective is "high endurance".
  • PixyMisa - Monday, March 30, 2020 - link

    Maybe the target market is endurance-oriented rather than capacity - 140TBW is a lot for a 64GB SD card.
  • Samus - Tuesday, March 31, 2020 - link

    If they take 256GB of TLC and make 32GB SLC, the card is effectively going to become 64GB total capacity.
  • Duncan Macdonald - Tuesday, March 31, 2020 - link

    4K p60 video has a basic data requirement of 3840*2160*60*3 bytes/sec which is 1,492,992,000 bytes /sec (almost 1.5 GB/sec) (HDR multiplies that rate by 1.25). Inter frame and intra frame compression reduce this amount drastically but the level of compression that can be applied in a camera without leading to excessive scene degradation with rapidly changing scenes requires over 50 MB/sec recording rate. (There are cameras which compress further (eg on phones) but severe degradation occurs on any rapidly changing scene.) Off camera compression where the video is passed without compression to a separate recorder and finally compressed on a computer allow for lower final average bit rates without excessive degradation.
    YouTube videos with a bit rate around 25Mbps show degradation even on fairly static scenes at 1080p.
  • Guspaz - Tuesday, March 31, 2020 - link

    Professional cameras and recorders don't normally use interframe compression, though. They use intraframe compression or raw codecs (which are also intraframe).
  • Xajel - Tuesday, March 31, 2020 - link

    Hope to see more to come with good pricing, these can bee good for Raspberry pi's with data logging, thought log2ram is still a must for any RPi logging setup...

Log in

Don't have an account? Sign up now