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Why SSDs Won't Replace Hard Drives
storagedude writes "Flash drive capacities have been expanding dramatically in recent years, but this article says that's about to change, in part because of the limits of current lithography technology. Meanwhile, disk drive densities will continue to grow, which the author says will mean many years before solid state drives replace hard drives — if they ever do. From the article: 'The bottom line is that there are limits to how small things can get with current technology. Flash densities are going to have data density growth problems, just as other storage technologies have had over the last 30 years. This should surprise no one. And the lithography problem for flash doesn't end there. Jeff Layton, Enterprise Technologist for HPC at Dell, notes that as lithography gets smaller, NAND has more and more troubles — the voltages don't decrease, so the probability of causing an accidental data corruption of a neighboring NAND goes up. "So at some point, you just can't reduce the size and hope to not have data corruption," notes Layton.'"
With SSDs, I'm sure there is always another axis of improvement, similar to with CPUs, when you hit a wall with them, go SMP. When SMP doesn't scale, crank up the clock speed, etc.
What I wonder is what can be focused on to make SSDs be able to store more. We can always stick more chips in an enclosure, and the cooling needs for SSDs are far less than the cooling needed for CPUs.
It is kind of funny how the article seems to be non-inflammatory, saying that replacement won't happen "soon", but the headline reads like a nice troll. Anyone think the editor chose the headline for page hits?
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
Correct me if I'm wrong here - and I usually am wrong -
I'm usually right... but that statement might be one of the exceptions. :)
TFA doesn't actually make any arguments about price directly. It indirectly suggests price of the drives is related to lithography resolution, but provides nothing to back that up.
It seems to me that over time as yields on current technology increase and fab costs are recouped, the price of current technology will go down.
It's a basic maxim of the silicon industry that cost is directly proportional to die area. To simplify, you can consider the silicon fab to have a fixed cost per wafer. Therefore the more die fit on a wafer, the cheaper each chip becomes. The two main ways to do this are by reducing the amount of functionality on each chip (undesirable when the goal is to increase capacity), or to move to a smaller lithography so you can fit many more die on a wafer. While new lithography generations have frequently allowed greater performance, even if they don't they are deployed anyway because it reduces cost for the manufacturer.
Yield improvements and paying off R&D both will help cost, but only to a limited extent. Yields for a production lithography should already be quite high and will asymptotically approach 1. Once R&D is payed off the cost will drop, but there still remains a very large fixed cost per wafer. Neither is going to come close to the cost benefit of being able to, say, go from a 45nm to 32nm process and get roughly 40% more die per wafer.
So yeah price will come down for other reasons, but in the long term price reductions in flash memory devices are going to depend on using smaller lithographies just like it does for other semiconductor devices. The author probably just didn't think to explain this aspect of it, since it's such a well-known aspect of the silicon industry.
On the other hand, people were saying that CMOS processes used in CPUs were going to reach fundamental limits 20 years ago. And 15. And 10. And 5. And oh sure, some of those limits were reached, but then clever people worked around them. The statement in the article amounts to "We can't just blindly reduce lithography size without changing anything else indefinitely", which is true but also kinda pointless since the people working on smaller lithographies for flash are probably aware. In the end exponential progressions like this can't last for ever, but I'm not about to tell the process engineers that they aren't going to be able to find enough tricks to keep it going long enough.
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The most interesting man I never met lived in a small house near the beach, had newspapers and old chairs and magazines piled to the ceiling in every room. Must have had a thousand cubic feet of Life Magazine. A most exciting fellow. What the man could have done with a proper warehouse, who knows?
What will finally put Seagate out of business is the universal porn compressor: an algorithm to produce almost any image with a pornographic payload (validated through fMRI studies). Finally we can eliminate women from sex. It'll be great.