Intel-Micron Flash Technologies just issued another increase in NAND density. This one’s manages to put 8GB on a single chip with MLC(2) technology in a 167mm square package or roughly a half inch per side.
You may recall that Intel-Micron Flash Technologies (IMFT) is a joint venture between Intel and Micron to develop NAND technology chips. IMFT chips can be used by any vendor and typically show up in Intel SSDs as well as other vendor systems. MLC technology is more suitable for use in consumer applications but at these densities it’s starting to make sense for use by data centers as well. We have written before about MLC NAND used in the enterprise disk by STEC and Toshiba’s MLC SSDs. But in essence MLC NAND reliability and endurability will ultimately determine its place in the enterprise.
But at these densities, you can just throw more capacity at the problem to mask MLC endurance concerns. For example, with this latest chip, one could conceivably have a single layer 2.5″ configuration with almost 200GBs of MLC NAND. If you wanted to configure this as 128GB SSD you could use the additional 72GB of NAND for failing pages. Doing this could conceivably add more than 50% to the life of an SSD.
SLC still has better (~10X) endurance but being able to ship 2X the capacity in the same footprint can help. Of course, MLC and SLC NAND can be combined in a hybrid device to give some approximation of SLC reliability at MLC costs.
IMFT made no mention of SLC NAND chips at the 25nm technology node but presumably this will be forthcoming shortly. As such, if we assume the technology can support a 4GB SLC NAND in a 167mm**2 chip it should be of significant interest to most enterprise SSD vendors.
A couple of things missing from yesterday’s IMFT press release, namely
- read/write performance specifications for the NAND chip
- write endurance specifications for the NAND chip
SSD performance is normally a function of all the technology that surrounds the NAND chip but it all starts with the chip. Also, MLC used to be capable of 10,000 write/erase cycles and SLC was capable of 100,000 w/e cycles but most recent technology from Toshiba (presumably 34nm technology) shows a MLC NAND write/erase endurance of only 1400 cycles. Which seems to imply that as the NAND technology increases density write endurance rates degrade. How much is subject to much debate and with the lack of any standardized w/e endurance specifications and reporting, it’s hard to see how bad it gets.
The bottom line, capacity is great but we need to know w/e endurance to really see where this new technology fits. Ultimately, if endurance degrades significantly such NAND technology will only be suitable for consumer products. Of course at ~10X (just guessing) the size of the enterprise market maybe that’s ok.
