What they say about the relentless pace of technology is true, as if it was ever in doubt to begin with. IMFT, the joint venture between Intel Corp and Micron Technology, has today unveiled two notable advances in NAND flash technology – an announcement with two major parts.
First up is the announcement of the mass production of 64Gb 20nm MLC NAND. Currently, many popular SSDs utilize IMFT’s 25nm NAND technology. As the cost of NAND constitutes the vast majority of the cost of solid-state drives, the die shrinkage should help make <$1 per GB SSDs a reality in 2012. Even better, write endurance is expected to remain the same as current 25nm Intel & Micron NAND flash.
Interestingly, the use of planar cell structure and High-K metal gates is credited as the contributing reason for preserving the write endurance. This would be the same high-k metal gate technology Intel began utilizing in its processors since the 45nm node.
Next up is the showcasing of a new 128Gb NAND chip. No bigger than a fingernail, this MLC NAND literally doubles the current density of MLC flash memory cells. It is also built on the same 20nm process mentioned above, but things quickly begin to differ from there. This new 128Gb chip will meet the upcoming high-speed ONFI 3.0 specification to “achieve speeds of 333 megatransfers per second (MT/s)…”
By comparison, current Intel 25nm NAND is capable of 166MT/s. Given that read speeds are bottlenecked by the interface, this will provide substantial increases in read performance in any SSDs utilizing these 128Gb MLC NAND devices, although ONFI 3 and the change to 16KB pages will doubtlessly boost write performance considerably as well. (A megatransfer per second is more like a measure of IOPS and therefore isn’t directly comparable to bytes per second).
The additional performance improvements the ONFI 3.0 specification will bring should be awesome to behold, although hopefully “SATA Express” will make an appearance in time given the new current SATA III standard is almost already maxed out. But regardless, there are more important advantages for the new 128Gb flash when it arrives. A die-shrinkage results in lower cost of production because less silicon is required to produce the same chip. But doubling the capacity of a NAND chip is slightly different; it literally doubles the capacity of the 64Gb NAND chips without appreciably changing the current die area required for production. In other words, the same size chip can now deliver twice the capacity at the same price. The price per GB can halve as the resulting NAND chip will require the same amount of silicon to produce.
Although it won’t reach mass production until the middle of 2012, once it does the 128Gb NAND could quickly make its way to devices by the end of 2012 or the start of 2013. The combination of a die shrinkage and doubling of NAND density should ensure that SSD prices will drop significantly by mid 2013, by my off-the-cuff estimate 60-70 cents a GB for SSDs seeming reasonable with plenty of margin left for improvement. In any case, the future of SSDs is certainly looking as good as ever.