Enterprise SSDs

Comparing SSDs to Tomatoes

TomatoA few years ago The SSD Guy posted an analogy that Intel’s Jim Pappas uses to illustrate the latency differences between DRAM, an SSD, and an HDD.  If we look at DRAM latency to be a single heartbeat, then what happens when we scale that timing up to represent SSDs and HDDs?  How many heartbeats would it take to access either one, and what could you do in that time?

I still think it’s a pretty interesting way to make all these latency differences easier to understand.

Just recently I learned of a Rich Report video of a 2015 presentation in which Micron’s Ryan Baxter uses a different and equally interesting analogy based on tomatoes.

Tomatoes aren’t the first thing that comes to my mind when I think about SSDs, but this video may change my way of thinking!

The tomato slide, 9:30 into the presentation, is Continue reading

Getting the Most from Data Center SSDs

2017-09-19 Calypso Real World Workload TestMy friend and associate Eden Kim of Calypso Systems has published a new white paper on real workloads for SSDs.

This is the company that has helped the Storage Networking Industry Association (SNIA) to develop performance tests for SSDs that get past the issues that plague SSD users: Yes, it does well when it’s new, but how will an SSD perform after a year or two of service?

Calypso has recently published a new White Paper entitled: Datacenter Server Real World Workloads.  This document analyzes real-life datacenter server workloads and performance to provide important insight into how an SSD might perform in actual environments rather than in synthesized workloads.  It compares data center class SSDs against SAS HDDs to take a lot of the guessing out of issues about IOPS requirements, endurance needs, and so forth by comparing the measured activity over 24 hours of a 2,000-outlet retail chain web portal running SQL.

The tests in the paper represent a Continue reading

IBM Aligns Itself with High Speed NVMe-based Storage

NVMe LogoIBM has announced that it is developing Non-Volatile Memory Express (NVMe) solutions to provide significantly lower latency storage.

NVMe is an interface protocol designed to replace the established SAS and SATA interfaces that are currently used for hard drives and SSDs. Coupled with the PCIe hardware backplane, NVMe uses parallelism and high queue depths to significantly reduce delays caused by data bottlenecks and move higher volumes of data within existing flash storage systems.

IBM has set itself to the task of optimizing the entire storage hierarchy, from the applications software to flash storage hardware, and is re-tooling the end-to-end storage stack to support NVMe. The company recognized years ago that both hardware and software would need to be redesigned to satisfy the needs of ultra-low latency data processing.

The company last year released products with Continue reading

Comparing Wear Figures on SSDs

DWPD TBW GB/Day TriangleI have been receiving questions lately from people who are puzzled when companies use different parameters than their competitors use to specify the endurance of their SSDs.  How do you compare one against the other?  Some companies even switch from one parameter to another to define the endurance of different SSDs within their product line.

I have found that Intel uses three different endurance measures for its products: DWPD (drive writes per day), TBW (terabytes written), and GB/day.

There’s not any real difference between any of these measures – each one is one way of stating how many times each of the SSD’s locations can be overwritten before the drive has gone past its warrantied life.

The relationships between these three measures are illustrated in this post’s graphic.  You can click on it to see an expanded version.  It’s all pretty simple.  We’ll spell out the relationships in detail below, but in brief, if you want to compare Continue reading

NGD’s 24TB SSD Is Just The First Step

NGD LogoWith the tagline: “Bringing intelligence to storage” start-up NGD Systems, formerly known as NexGen Data, has announced a 24 terabyte SSD that the company claims to be the highest-capacity PCIe/NVMe device available.

The read-optimized Catalina SSD employs a lot of proprietary NGD technology: Variable rate LDPC error correction, unique DSP (digital signal processing) algorithms, and an “Elastic” flash transition layer (FTL), all embodied in an NGD-proprietary controller.  This proprietary technology allows Catalina to offer enterprise performance and reliability while using TLC flash and less DRAM than other designs.

NGD claims that the product is already shipping and is being qualified by major OEMs.

Based on some of the company’s presentations at past years’ Flash Memory Summits the controller has been carefully balanced to optimize cost, throughput, and heat.  This last is a bigger problem than most folks would imagine.  At the 2013 Hot Chips conference a former Violin Memory engineering manager told the audience Continue reading

Intel Announces Optane SSDs for the Enterprise

Intel-Optane-SSDThis week Intel announced the Optane SSD DC P4800X Series, new enterprise SSDs based on the company’s 3D XPoint memory technology which Intel says is the first new memory technology to be introduced since 1989.  The technology was introduced to fill a price/performance gap that might impede Intel’s sales of high-performance CPUs.

Intel was all aglow with the promise of performance, claiming that the newly-released SSDs offer: “Consistently amazing response time under load.”

Since the early 1990s Intel has realized that it needs for the platform’s performance to keep pace with the ongoing performance increases of its new processors.  A slow platform will limit the performance of any processor, and if customers don’t see any benefit from purchasing a more expensive processor, then Intel will be unable to keep its processor prices high.

Recently NAND flash SSDs have helped Intel to improve the platform’s speed, as did the earlier migration of Continue reading

Managing SSDs Using Machine Learning

Focusrite Recoring Console - photo by JacoTenSSDs use a huge number of internal parameters to achieve a tricky balance between performance, wear, and cost.  The SSD Guy likes to compare this to a recording studio console like the one in this post’s graphic to emphasize just how tricky it is for SSD designers to find the right balance.  Imagine trying to manage all of those knobs!  (The picture is JacoTen’s Wikipedia photo of a Focusrite console.)

Vendors who produce differentiated SSDs pride themselves in their ability to fine-tune these parameters to achieve better performance or endurance than competing products.

About a year ago I suggested to the folks at NVMdurance that they might consider applying their machine learning algorithm to this problem.  (The original NVMdurance product line was described in a Memory Guy post a while ago.)  After all, the company makes a machine learning engine that tunes the numerous internal parameters of a NAND flash chip to extend the chip’s life while maintaining the specified performance.  SSD management would be a natural use of machine learning since both SSDs and NAND flash chips currently use difficult and time-consuming manual processes to find the best mix of parameters to drive the design.

Little did I know that NVMdurance’s researchers Continue reading

Latency, IOPS & NVDIMMs

Latency vs IOPS Persectives - PowerPointSometimes it’s enlightening to compare several viewpoints on similar data.  At yesterday’s SNIA Persistent Memory Summit a number of presentations provided interesting overlapping views on certain subjects.

One of particular interest to The SSD Guy was latency vs. IOPS.  Tom Coughlin of Coughlin Associates and I presented the findings from our recently-published IOPS survey report and in Slide 19 displayed the basic chart behind this post’s graphic (click to enlarge, or, better yet, right-click to open in a new tab). This chart compares how many IOPS our respondents said they need for the storage in their most important application, and compared that to the latency they required from this storage.  For comparison’s sake we added a reference column on the left to roughly illustrate the latency of various standard forms of storage and memory.

You can see that we received a great variety of inputs spanning a very wide range of IOPS and latency needs, and that these didn’t all line up neatly as we would have anticipated.  One failing of this chart format is that it doesn’t account for multiple replies for the same IOPS/latency combination: If we had been able to include that the chart would have shown a clearer trendline running from the top left to the lower right.  Instead we have a band that broadly follows that trend of upper-left to lower-right.

Two other speakers presented the IOPS and latency that could be Continue reading

Micron Unveils New 5100 Enterprise SSDs

Micron's 5100 SSD FamilyMicron has announced a new line of Enterprise SSDs that it has named the 5100 family.  The three members of the family are designated by different suffixes: 5100 ECO, 5100 PRO, and 5100 MAX, as listed in the table below.

The three models support the same maximum read IOPS performance, but have a wide range of write IOPS figures, endurance (measured in DWPD = Drive Writes per Day), and maximum capacities.

All of these SSDs are based on Micron’s 3-bit 3D NAND.  Micron has been aggressively ramping its 3D NAND technology since it began shipments in earnest last June.

The three SSD models are designed using the same fundamental firmware architecture, which Micron has named FlexPro, to yield consistent performance and reliability across the family, and with the hopes that customers will be able to qualify all three models in a single effort, which would provide one more reason for users to source their Continue reading

IBM Refreshes Broad Swath of Flash Offerings

IBM Storwize All FlashYesterday IBM unveiled a sweeping update of its existing flash storage products.  These updates cover a range of products, including IBM Storwize All Flash arrays: V7000F, V7000 Gen2+, and V5030F, the FlashSystem V9000, the IBM SAN Volume Controller (SVC), and IBM’s Spectrum Virtualize Software.

The company referred to this effort as a part of a: “Drumbeat of flash storage announcements.”  IBM has a stated goal of providing its clients with: “The right flash for the right performance at the right price.”

IBM’s representatives explained that the updates were made possible by the fact that the prices of flash components have been dropping at a rapid pace while reliability is on the rise.  The SSD Guy couldn’t agree more.

Here’s what IBM announced:

Starting from the low end and moving up, the V5030F entry-level/midrange array is an Continue reading