SanDisk ships 'X4' flash chips

SanDisk said Monday that it is shipping memory chips that will allow consumers to store more data on tiny Secure Digital flash cards.

SanDisk X4 chip

(Credit: SanDisk)

The Milpitas, Calif., company's X4 technology packs four bits of data into each memory cell. To date, flash memory chipmakers typically stored one bit or two bits per cell. Each individual die--or chip--holds 64 gigabits of data, or 8 gigabytes. This is the highest capacity per die in the industry, according to SanDisk.

The technology is not yet shipping in cutting-edge retail products, however: it is currently being used in 8GB and 16GB SDHC (Secure Digital High Capacity) cards as well as 8GB and 16GB Memory Stick PRO Duo cards, the company said.

Future related technology from SanDisk--possibly not based on current X4--is expected to yield SD flash cards that hold 64GB of data and larger capacities. Currently, mainstream SanDisk SD cards top out at 32GB.

Flash memory cards sold at retailers are typically not as reliable as solid-state drives--which also use flash chips--sold with laptops. And the higher the density per chip and the more bits per cell, the bigger the challenge for maintaining data reliability. SanDisk says it has met this challenge.

"Our challenge with X4 technology was to not only deliver the lower costs inherent to 4-bits-per-cell but to do so while meeting the reliability and performance requirements of industry standard cards," Sanjay Mehrotra, SanDisk's president and chief operating officer, said in a statement.

But X4 will, for the time being, be hampered by poorer performance and endurance than X3 (3-bits-per-cell) technology, said Gregory Wong, founder and principal analyst at Forward Insights, which does research on flash memory technology.

The memory technology itself--the 4 bits per cell 64-gigabit memory--is codeveloped and co-owned by SanDisk and Toshiba. The X4 controller technology is solely owned by SanDisk.

[Lerianis3]

Are these faster or slower than current offerings, and will you able to use them in regular old SD slots? Unless the answer is yes, that they are backwards compatible with the SD slots in computers like the ones that I have, these aren't going to catch on very fast or at all.

[solitare_pax]

I believe it would have to be an SD-HC card, because they had to revise the original SD specs to get a theoretical upper limit of 1 tetrabyte on a chip.

It would be nice to know for certain though.

[TotallyMadeUpName]

Reread the article.

"The technology is shipping now in 8GB and 16GB SDHC (Secure Digital High Capacity) cards"

[Masterface7]

SDHC seemed to catch on pretty fast over regular sd cards and they dont work in regular sd card slots. You have to buy new card readers and get firmware updates yet people still buy them. So i think any expansion of memory especially to this degree will get eaten up by the mainstream very rapidly not to mention they should work in sdhc card readers.

[bdg2]

They're normal SDHC but likely to be slower and less reliable.

[chuchucuhi]

Well it will go along way for SDHCX and reaching that 2TB limit, hehe.

[basraw]

So are current cards not reliable or are they reliable with industry standards? Which is it?

Are we talking SLC or MLC solid state drives?

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"Flash memory cards sold at retailers are typically not as reliable as solid-state drives--which also use flash chips--sold with laptops. And the higher the density per chip and the more bits per cell, the bigger the challenge for maintaining data reliability. SanDisk says it has met this challenge.

"Our challenge with X4 technology was to not only deliver the lower costs inherent to 4-bits-per-cell but to do so while meeting the reliability and performance requirements of industry standard cards,""

[bdg2]

X4 will be harder to make reliable than X3 was.

X4 is only 33% higher capacity than X3 but is arguably 100% harder to make reliable.

X4, X3 and what could be called X2 are MLC.

What could be called X1 is SLC.