This months it’s back to storage and our annual wrap-up on the Flash Memory Summit Conference with Jim Handy, General Director of Objective Analysis. Jim’s been on our show 5 times before and is a well known expert on NAND and SSDs (as well as DRAM and memory systems). Jim also blogs at TheSSDGuy.com and TheMemoryGuy.com just in case you want to learn more.
FMS went virtual this year and had many interesting topics including how computational storage is making headway in the cloud, 3D QLC is hitting the enterprise with PLC on the way, and for a first at FMS, a talk on DNA storage (for more information on this, see our podcast with CatalogDNA). Jim’s always interesting to talk with to help us understand where the NAND-SSD industry is headed. Listen to the podcast to learn more.
Jim mentioned that the major NAND vendors are all increasing the number of layers for their 3D NAND, and it continues to scale well. Most vendors are currently shipping ~100 layer NAND, with Micron doing more than that. And vendor roadmaps are looking at the possibility of 200 layers or more. Jim doesn’t think anyone knows how high it can go.
Another advantage of 3D NAND is it can be used to make bigger bit cells and thus have better endurance. From Jim’s perspective more electrons per cell means a better more resilient bit cell.
Many vendors in the nascent persistent memory industry were all hoping that NAND would stop scaling at some point and they would be able to pick up the slack. But NAND manufacturers found 3D and scaling hasn’t stopped at all. This has relegated most persistent memory vendors to a small niche market with the exception of Intel (and Micron).
Jim said that Intel is losing money on Optane every year, ~$5B so far. But Intel knows that chip profitability is tied to economies of scale, volumes matter. With enough volume, Optane will become cheap enough to manufacture that they will make buckets of money from it.
Interestingly, Jim said that DRAM scaling is slowing down. That means there may be an even bigger market for something close to DRAM access speeds, but with increased density and lower cost. Optane seems to fit that description very well.
Jim also mentioned that computational storage is starting to see some traction with public cloud vendors. Computational storage adds generic compute power to inside an SSD which can be used to perform storage intensive functions out at the SSD rather than transferring data into the CPU for processing. This makes sense where a lot of data would need to be transferred back and forth to an SSD and where computational cycles are just as cheap out on the SSD as in the server. For example, for data compression, search, and video transcoding, computational storage can make a lot of sense. (See our podcast with NGD systems for more informaiton).
In contrast, Open-Channel SSDs are making dumb SSDs, or SSDs without any flash translation layer or other smarts needed to make NAND work as persistent storage bin the enterprise. There’s a small group of system providers that want to perform all this functionality at a global scale (or across multiple SSDs) rather than at the local, SSD drive level.
Another topic that hit it’s stride this year at FMS2020 was Zoned Name Spaces (ZNS). ZNS partitions an SSD into separately addressable segments, to allow higher performing sequential (write) access within those zones. As SSD capacity has increased, IO activity has sky-rocketed and this has led to an “IO blender” effect. Within an IO blender, it’s impossible to understand which IO is following a sequential pattern and which is not. ZNS is intended to solve that probplem
With ZNS SSDs, IOs doing sequential access can have their own partition and that way the SSD can understand its sequential IO and act accordingly. It turns out that sequential writes to NAND can perform much, much faster than random writes.
ZNS was invented for SMR (shingled magnetic recording) disks, because these overwrote portions of other tracks (like roof shingles, tracks on SMR disks overlap). We had heard about ZNS at FMS2019 but had thought this just a better way to share access to a single SSD, by carving it up into logical (mini-)volumes. Jim said that was also a benefit but the major advantage is being able to understand sequential IO and write to the SSD more effectively.
We talked some on the economics of NAND flash, disk and tape as storage media. Jim and I see this continuing a trend that’s been going on for years, where NAND storage cost $/GB ~10X more than disk capacity, and disk storage costs $/GB ~10X more than tape capacity. All three technologies continue their relentless pursuit of increasing capacity but it’s almost like train tracks, all three $/GB curves following one another into the future.
On the other hand, high RPM disk seems to have died, and been replaced with SSDs. Disk manufacturers have seen unit declines but the # GB they are shipping continues to increase. Contrary to a number of AFA system providers, disk is not dead and is unlikely to die anytime soon.
Finally, we discussed DNA storage and it’s coming entry into the storage market. It’s all a question of price of the drive and media technology, size of the mechanism (drive?) and read and write access times. At the moment all these are coming down but are not yet competitive with tape. But given DNA technology trends, there doesn’t appear to be any physical barrier that’s going to stop it from becoming yet another storage technology in the enterprise, most likely at a 10X $/GB cost advantage over tape…
Jim Handy, General Director, Objective Analysis
Jim Handy of Objective Analysis has over 35 years in the electronics industry including 20 years as a leading semiconductor and SSD industry analyst. Early in his career he held marketing and design positions at leading semiconductor suppliers including Intel, National Semiconductor, and Infineon.
A frequent presenter at trade shows, Mr. Handy is known for his technical depth, accurate forecasts, widespread industry presence and volume of publication.
He has written hundreds of market reports, articles for trade journals, and white papers, and is frequently interviewed and quoted in the electronics trade press and other media.