Some time ago Objective Analysis ran nearly 300 standard benchmarks on a PC with varying amounts of flash and DRAM and found that a dollar’s worth of flash provided a greater performance boost than a dollar’s worth of DRAM once the DRAM size grew above a certain minimum (1-2GB) depending on the benchmark.
You might wonder how this could possibly be true. Everyone knows that best way to improve any computing system’s performance is to add DRAM main memory. How could flash, which is orders of magnitude slower than DRAM, provide a bigger performance boost than DRAM?
It all makes sense if you think of the DRAM of something that is there only to make the HDD look faster. More is better, but if you can use a little less DRAM and add a large flash memory layer then disk accesses appear to speed up even more.
The benchmark data and the price/performance findings that are Continue reading
In essence it’s because both the HDD industry and the semiconductor industry have set goals for themselves to achieve 30% average annual price reductions. If they are both on the same trajectory, and if there’s an order of magnitude difference between HDD and SSD prices today, then there will be an order of magnitude difference in the future as well.
The 30% average annual decline in SSD prices has a convenient name: Moore’s Law. Although there’s no physical, economic, or other restriction behind Moore’s Law (so it’s not really a law at all) it serves as a guide for the industry. Chip makers set their sights at doubling the number of transistors on a chip every couple of years, and this equates to average annual price decreases of 30%.
The HDD business also Continue reading
On Friday Toshiba revealed its restructuring plans aimed at returning the company to profitability and growth through management accountability.
Of special interest to The SSD Guy was the fact that the company will refocus its semiconductor and HDD businesses, currently called the “Semiconductor & Storage Products Company” partly by giving it a new name: “Storage & Electron Devices Company”. This division will focus on the semiconductor group’s good prospects and profitability while maintaining a focus on the fact that SSDs and HDDs share a business. In the not-too-distant past Toshiba has run these two businesses separately.
The group plans to be “A pillar of income with Memories as a core business”. To achieve this, Toshiba has stated that it will enhance its NAND cost competitiveness by accelerating development of BiCS (Toshiba’s 3D NAND technology) and by expanding the SSD business. There are three parts to this Continue reading
In a joint press release, SanDisk and IBM announced support for each other’s products. The IBM Spectrum Scale filesystem will support SanDisk’s InfiniFlash all-flash array to provide a high-capacity high-speed software-defined storage system.
At first glance this may seem a little odd, since IBM sells its own all-flash array, the FlashSystem, which became an IBM product line when the company acquired Texas Memory Systems (TMS) back in 2012. That is not the case, though. IBM has been validating that its Spectrum Storage products will work with just about any storage type that its customers may want to use. Rather than narrowing this software’s support to only IBM storage systems, IBM is showing that Spectrum Scale is flexible enough to work with a multitude of solutions, supporting InfiniFlash the same as it does other internal server capacity and other external storage in the form of JBODs (“Just a Bunch of Disks”) or JBOFs (“Just a Bunch of Flash”).
In this case IBM has worked with SanDisk to validate that its Spectrum Scale storage management software works with InfiniFlash, just as it does with those many other storage solutions.
In the announcement IBM explains that Continue reading
The SSD Guy was recently asked whether HDDs would continue, at least through 2019, to remain preferable to SSDs as cost-effective high-capacity storage. The answer was “Yes”.
Longtime readers will note that I steadfastly maintain that HDD and SSD gigabyte prices are unlikely to cross for a very long time. Historically, a gigabyte of NAND flash has cost between ten to twenty times as much as a gigabyte of HDD. Let’s look at where Objective Analysis expects things to go by 2019.
Our current projections call for NAND price per gigabyte to reach 4.4 cents in 2019. I would expect for HDD to still be 1/10th to 1/20th of that price. Most likely 1/10th, since we expect for NAND flash to be in a significant oversupply at that time and will be selling at cost.
If HDD prices continue to hover around $50, then a 2019 HDD price of 0.44 to 0.22 cents per gigabyte (1/10th to 1/20th of the price of NAND flash) would imply an average HDD capacity of 11-23TB.
A couple of weeks ago, on December 2, 2015, Western Digital’s HGST introduced its Continue reading
This Sunday (Sept. 20, 2015) I will be presenting my company’s findings on the 3D XPoint memory that was introduced by Intel and Micron in July. I will be speaking at the Storage Networking Industry Association (SNIA) Storage Developer Conference (SDC) Pre-Conference Primer. You can click the name to be taken to the agenda.
This won’t be the only talk about persistent memory technology at the conference. Prior to my presentation storage consultants Tom Coughlin and Ed Grochowski will give an overview of advances in nonvolatile memories, and following my presentation will be two Intel talks.
Intel will be covering this new technology a lot during the conference. Of a total of 120 presentations at the conference and pre-conference primer, Intel will be presenting nine, seven of which directly name persistent memory or nonvolatile memory in the title. Other firms will also be talking about NVM: AgigA, Calypso, HP, Pure Storage, and SMART Modular. Even Microsoft alludes to it in a couple of its presentation titles. Persistent memory is a hot issue.
So, the question for readers of The SSD Guy blog is: “Will this do away with SSDs?”
This is a question that was Continue reading
A couple of specifications for SSD endurance are in common use today: Terabytes Written (TBW) and Drive Writes Per Day (DWPD). Both are different ways to express the same thing. It seems that one vendor will specify endurance using TBW, while another will specify DWPD. How do you compare the two?
First, some definitions. “Terabytes Written” is the total amount of data that can be written into an SSD before it is likely to fail. “Drive Writes Per Day” tells how many times you can overwrite the entire capacity of the SSD every single day of its usable life without failure during the warranty period. Since both of these are guaranteed specifications, then your drive is most likely to last a lot longer than the number given by the SSD’s maker.
To convert between the two you must know the disk’s capacity and the warranty period. If drive maker gives you TBW but you want to know DWPD you would approach it Continue reading
A recent conversation with some fellow analysts revealed a puzzling set of claims. EMC, at its EMC World conference (May 3-7) claimed to be the leader in flash array shipments. The very next week, in the same Las Vegas hotel, IBM also claimed leadership in flash.
Who do you believe?
- EMC is counting XtremIO Arrays as units shipped and according to Gartner Group held the #1 market share position with a 31.1% share, which is over a ten percentage point share lead
- IBM is counting capacity of PBs shipped with all of their flash storage solutions: The FlashSystem 840, 900, V840, V9000, DS8000, plus the XIV systems, Storwize V7000, IBM Flash DAS, and IBM PCIe Adapters
- NetApp is the leader if you count total flash systems shipped (NetApp-branded plus privately-branded systems) spanning multiple years as their SANtricity operating system and E-Series platforms have sold over 750,000 units
- Pure Storage uses its 700% growth to show that it’s the #1 fastest-growing flash storage company
- Then, if you want to compare any vendor’s total all flash array (AFA) systems sold this past year against hybrid storage arrays, Nimble Storage beats any of the AFA vendors.
Yesterday SanDisk announced a new low-end family of SSDs that the company said would sell: “at a price point on par with HDDs. (Pricing comparison dependent upon capacity.)” The sub-headline states: “Z400s SSD Brings New Levels of Affordability to Replace Hard Drives…”
The release provided no actual prices to back up this claim.
So how does this work? Can you actually now buy a 1TB SSD for cheaper than a 1TB HDD? Not at all. Instead you have to look at things a little differently using a concept that I frequently explained five years ago when SSDs were pretty new – that very low capacity SSDs can be cheaper than HDDs.
This post’s graph plots this out. It’s a chart of HDD and SSD prices over a range of capacities. It’s on a log-log scale, but it works well on a standard linear chart as well. Note that prices are for 2010, and prices have come down significantly for both SSDs and HDDs since then. This means that the numbers on the X and Y axes need adjustment to bring them to today’s levels, but the shape of the curves would remain the same.
The red line represents SSD costs over the range of capacities, and the black line represents HDDs. Although HDDs are cheaper than SSDs Continue reading
From time to time IT managers ask The SSD Guy if there’s an easy way to compare SSDs made with MLC flash against those made using eMLC flash. Most folks understand that eMLC flash is a less costly alternative to SLC flash, both of which provide longer wear than standard MLC flash, but not everyone realizes that eMLC’s superior endurance comes at the cost of slower write speed. By writing to the flash more gently the technology can be made to last considerably longer.
So how do you compare the two? OCZ introduced MLC and eMLC versions of the same SSD this week, and this provides a beautiful opportunity to explore the difference.
As you would expect, the read parameters are all identical. This stands to reason, since Continue reading