Subject: Storage | February 14, 2017 - 06:51 PM | Jeremy Hellstrom
Tagged: tlc, slc, MX300, micron, imft, Dynamic Write Acceleration, DWA, crucial, 3DNAND, 3d nand
Last June Al took a look at the Crucial MX300 750GB and its ability to switch its cache dynamically from TLC to SLC, helping Crucial improve how they implemented this feature along the way. It proved to be a great value for the money; not the best performing drive but among the least expensive on the market. Crucial has since expanded the lineup and Hardware Canucks took a look at the 2TB model. This model has more than just a larger pool of NAND, the RAM cache has been doubled up to 1GB and the dynamic cache has more space to work in as well. Take a look at this economy sized drive in their full review.
"Crucial's newest MX300 series continues to roll on with a new 2TB version. This SSD may be one of the best when it comes to performance, price and capacity all combined into one package."
Here are some more Storage reviews from around the web:
- Crucial MX300 525GB SSD Review @ Neoseeker
- Silicon Power S57 240GB @ eTeknix
- Silicon Power S56 240GB @ eTeknix
- Transcend ESD400 256GB External SSD @ Kitguru
- QNAP TurboNAS TS-1635-8G 16-bay 10GbE NAS Server Review @ NikKTech
- Drobo 5c 5-Bay USB Type-C Self-Managing DAS @ eTeknix
Introduction, Dynamic Write Acceleration, and Packaging
Micron joined Intel in announcing their joint venture production of IMFT 3D NAND just a bit over a year ago. The industry was naturally excited since IMFT has historically enabled relatively efficient production, ultimately resulting in reduced SSD prices over time. I suspect this time things will be no different as IMFT's 3D Flash has been aiming high die capacities since its inception, and I suspect their second generation will *double* per-die capacities while keeping speeds reasonable thanks to a quad-plane design implemented from the start of this endeavor. Of course, I'm getting ahead of myself a bit as there are no consumer products sporting this flash just yet - well not until today at least:
Marketed under Micron's consumer brand Crucial, the MX300 is their first entrant into the consumer space, as well as the first consumer SSD sporting IMFT 3D NAND. Crucial is known for their budget-minded SSDs, and for the MX300 they chose to go with the best cost/GB they could manage with what they had to work with. That meant putting this new 3D NAND into TLC mode. Now there are many TLC haters out there, but remember this is 3D NAND. Samsung's 850 EVO can exceed 500 MB/sec writes to TLC at its 500GB capacity point, and this MX300 is a product that is launching with *only* a 750GB capacity, so its TLC speed should be at least reasonable.
(the return of) Dynamic Write Acceleration
Dynamic Write Acceleration in action during a sequential fill - that last slowest part was my primary concern for the mX300.
TLC is not the only story here because Crucial has included their Dynamic Write Acceleration (DWA) technology into the MX300. This is a tech where the SSD controller is able to dynamically switch flash programming modes of the flash pool, doing so at the block level. This appears to be a feature unique to IMFT flash, as every other 'hybrid' SSD we have tested had a static SLC cache area. DWA's ability to switch flash modes on-the-fly has always fascinated me on paper, but I just haven't been impressed by Micron's previous attempts to implement it. The M600 was a bit all over the place on its write consistency, and that SSD was flipping blocks between SLC and MLC. With the MX300 flipping between SLC and *TLC*, there was a possibility of far more noticeable slow downs in the cases where large writes were taking place and the controller was caught trying to scavenge space in the background.
New Latency Percentile vs. legacy IO Percentile, shown here highlighting a performance inconsistency seen in the Toshiba OCZ RD400. Note which line more closely represents the Latency Distribution (gray) also on this plot.
Subject: Storage | June 13, 2016 - 03:46 AM | Allyn Malventano
Tagged: XPoint, tlc, Stony Beach, ssd, pcie, Optane, NVMe, mlc, Mansion Beach, M.2, kaby lake, Intel, imft, Brighton Beach, 3DNAND, 3d nand
For those unaware, XPoint (spoken 'cross-point') is a new type of storage technology that is persistent like NAND Flash but with speeds closer to that of RAM. Intel's brand name for devices implementing XPoint are called Optane.
Starting at the bottom of the slide, we see a new 'System Acceleration' segment with a 'Stony Beach PCIe/NVMe m.2 System Accelerator'. This is likely a new take on Larson Creek, which was a 20GB SLC SSD launched in 2011. This small yet very fast SLC flash was tied into the storage subsystem via Intel's Rapid Storage Technology and acted as a caching tier for HDDs, which comprised most of the storage market at that time. Since Optane excels at random access, even a PCIe 3.0 x2 part could outmaneuver the fastest available NAND, meaning these new System Accelerators could act as a caching tier for Flash-based SSDs or even HDDs. These accelerators can also be good for boosting the performance of mobile products, potentially enabling the use of cheaper / lower performing Flash / HDD for bulk storage.
Skipping past the mainstream parts for now, enthusiasts can expect to see Brighton Beach and Mansion Beach, which are Optane SSDs linked via PCIe 3x2 or x4, respectively. Not just accelerators, these products should have considerably more storage capacity, which may bring costs fairly high unless either XPoint production is very efficient or if there is also NAND Flash present on those parts for bulk storage (think XPoint cache for NAND Flash all in one product).
We're not sure if or how the recent delays to Kaby Lake will impact the other blocks on the above slide, but we do know that many of the other blocks present are on-track. The SSD 540s and 5400s were in fact announced in Q2, and are Intel's first shipping products using IMFT 3D NAND. Parts not yet seen announced are the Pro 6000p and 600p, which are long overdue m.2 SSDs that may compete against Samsung's 950 Pro. Do note that those are marked as TLC products (purple), though I suspect they may actually be a hybrid TLC+SLC cache solution.
Going further out on the timeline we naturally see refreshes to all of the Optane parts, but we also see the first mention of second-generation IMFT 3DNAND. As I hinted at in an article back in February, second-gen 3D NAND will very likely *double* the per-die capacity to 512Gbit (64GB) for MLC and 768Gbit (96GB) for TLC. While die counts will be cut in half for a given total SSD capacity, speed reductions will be partially mitigated by this flash having at least four planes per die (most previous flash was double-plane). A plane is an effective partitioning of flash within the die, with each section having its own buffer. Each plane can perform erase/program/read operations independently, and for operations where the Flash is more limiting than the interface (writes), doubling the number of planes also doubles the throughput. In short, doubling planes roughly negates the speed drop caused by halving the die count on an SSD (until you reach the point where controller-to-NAND channels become the bottleneck, of course).
IMFT XPoint Die shot I caught at the Intel / Micron launch event.
Well, that's all I have for now. I'm excited to see that XPoint is making its way into consumer products (and Storage Accelerators) within the next year's time. I certainly look forward to testing these products, and I hope to show them running faster than they did back at that IDF demo...