New
#1
As one that doesn't have a SSD, I would tend to want to wait for the 50mm to come down in price, rather than buy the 20mm with less than half the life expectancy.
NAND flash is getting smaller, again. Should be out by the end of the year.
We just started testing SSDs based on IMFT 25nm NAND Flash and look at what Intel/Micron just announced? The first 8GB MLC NAND device built on a 20nm process. This is obviously an announcement of pre-production silicon, it’ll take IMFT until the second half of this year (at least) to start shipping production quality 20nm NAND.
At 50nm IMFT NAND was good for 10,000 program/erase cycles (rated, not actual). The move to 34nm dropped that to 3000 - 5000 program erase cycles, a value that was maintained with the move to 25nm. I asked Micron how long NAND will last at 20nm and was told that p/e cycles are comparable to where 25nm was at a similar point in its development cycle. Micron expects quality to ramp over time and ultimately hit a similar point to existing 25nm NAND, which is good for controller manufacturers as it means any ECC/NAND redundancy efforts they have already implemented should support the new 20nm product.
An 8GB 2-bit-per-cell MLC NAND device built at 20nm has a die area of 118mm2, down from 167mm2 at 25nm. A single 8GB NAND device wasn’t built at 34nm.
IMFT is on a 15 - 18 month process cadence, meaning this transition was of course planned for in advance. The first 20nm NAND is being manufactured at the IMFT Fab in Lehi, Utah, which is currently producing 25nm NAND. Some equipment upgrades are necessary to support 20nm. IMFT will also transition its fabs in Manassas, VA and Singapore to 20nm at a later point.
For consumers there’s an obvious win. We need smaller transistor geometries to reduce the cost of NAND, which ultimately reduces the cost of SSDs. The days of 50% annual price reductions are over however, expect to see a conservative 20 - 30% drop in price for SSDs that use 20nm NAND over 25nm NAND.
Source...
As one that doesn't have a SSD, I would tend to want to wait for the 50mm to come down in price, rather than buy the 20mm with less than half the life expectancy.
Thanks David nice read. My understanding is that Intel's new 510 ssd is going to stay with the 34nm HAND for reliability reasons.
Yes, that is a big part of it.
They might have had the 510 in the works for a while with plans to use the 25nm nand, but went with the 34nm nand due to the OCZ 25nm uproar and negative results.
The 25nm reduced speed was mainly due to less nand chips and therefore fewer channels which result in a reduction in speed.
There is a lot of articles trying to assure everyone that 25nm nand is ok and reliable. Not sure if this is being pushed by the manufacturers or how much of it is true. Only time will tell.
New hardware tech is always going to be like this.
Hope they will start coming down in the next couple of months, will be interesting to see what they are at the end of the year.