A post earlier this year by CNET News.com's Stephen Shankland pondering how he should store photos while traveling got me thinking about the same question.
I can't claim to have come up with "the answer," but I've thought about the issues, read through some discussions about what people consider best practices, and have tried to roughly quantify relative failure rates. What's right for you will depend on priorities and circumstances, but hopefully the following will offer some food for thought.
Real-world failure rates are hard to come by. However, having been the owner of a variety of laptops and other devices with hard disk drives, a 1:100 drive failure rate in a portable device over the course of a month's vacation doesn't seem out of line. Flash memory fails too. Anecdotal information from a couple of dealers (based on product returns) suggests that a 1:1000 rate is a reasonable stake in the ground--10x the reliability of disk. Further complicating the story is that some errors are recoverable, but you'd probably better stop using the card when you have a problem.
That's the hardware. Then there's the wetware--i.e. you.
This one's even harder to quantify. However, speaking for myself, I'm always misplacing loose memory cards. Furthermore, procedures that involve a lot of multi-step copying, editing, and so forth offer lots of potential to erase something that you thought you backed up or for an operation to otherwise fail without your knowledge. Or you might, like me, sometimes just do something really dumb. Also, consider theft and other forms of loss beyond your control.
Add it all up and my guess is that, for most people, minimizing the possibility of human error is more important than incrementally reducing the impact of a potential hardware failure.
With those reliability estimates and human realities as a baseline, here are my thoughts for some reasonable practices:
- If at all economically feasible, carry enough flash memory to hold all your photos. Flash has a good 10x the reliability of hard disks, more when you consider that it's probably going to be OK even if you drop it or run it through the washing machine.
- Common wisdom is that name brands are, in the aggregate, more reliable, and some higher-end cards also come with data recovery software. This seems reasonable. However, I've never seen actual data to bolster this belief--only random stories about crappy off-brand cards purchased on eBay. One data recover company notes that differences in build quality are indeed part of the reliability story but goes on to say it doesn't correlate in any consistent way to brand.
- Because photos can sometimes be recovered from memory cards after they've had a problem, it's a good idea to have at least one backup card. That way, if there's a problem, you can take the card out of the camera and work on it when you get home. Messing with it in the field is a recipe for losing data that could otherwise have been retrieved.
- A lot of people advocate putting fewer eggs in one basket. That is, they suggest using multiple smaller cards rather than one or two larger ones. This is hard to argue against so long as you develop a good system to ensure you don't lose the spare cards or accidentally erase or otherwise mess something up while you're swapping them around. Given overall flash reliability, I don't see this as a particular win--and may even be a net loss if taken to the extreme of some complicated scheme of rotating cards in and out of the camera.
- Although I tend not to bother, making a periodic hard disk backup of your memory cards is good belt-and-suspenders practice. If you're traveling with other people, a hard disk is also a good way to trade pictures. A computer is one possibility. Hard disk-based media players or portable devices specifically designed for the purpose are others.
- If you can't keep everything on flash, then you obviously need to copy it somewhere. Based on the numbers I threw out above, I wouldn't trust a single hard disk backup as my only copy of anything I really cared about. In this case, I'd want either a second hard disk or a way to burn a copy to DVD. (One advantage of making DVDs is that you can potentially mail a copy to yourself at home. (Laptop and DVDs were the solutions that Shankland eventually decided on.) If you have a bunch of spare thumb drives of reasonable capacity laying around, that may be another possibility.
- Cameras break too--maybe more so than any of the other parts we're talking about here, especially if you're in harsh conditions. I'm not sure of the final digital camera mortality rate on the Grand Canyon boating trip I took a couple of years back, but a fair number bit the dust. So definitely consider a backup camera. Sharing memory card format and/or batteries between main and backup is nice, if feasible.
Ultimately, it's all a matter of playing the odds of hardware failure, while keeping in mind all the dumb things that we can do to sabotage ourselves.
Is MRAM better than flash memory? That's a question a new venture business will try to answer.
Freescale MRAM chip
(Credit: Freescale Semiconductor)Former Motorola chip unit Freescale Semiconductor announced Monday that it has joined with several venture capital firms to form an independent company focused on MRAM (Magnetoresistive Random Access Memory).
The new company, EverSpin Technologies, will "expand its current portfolio of standalone MRAM and related magnetic-based products," the companies said in a statement.
MRAM uses magnetic materials combined with conventional silicon circuitry to deliver a high-performance permanent storage device.
But MRAM must compete with quickly evolving technologies like flash memory-based solid state drives. Flash memory is gaining ground because companies like Samsung, Toshiba, and Intel keep developing faster and higher-capacity devices.
(For more information on MRAM see MRAM-info. For an in-depth explanation of technologies used in MRAM see this explanation of electron spin and so-called spintronics.)
Freescale will transfer the MRAM technology, related intellectual property, and products to EverSpin Technologies and will retain an equity position in the new venture, the companies said. EverSpin is backed by venture firms New Venture Partners, Sigma Partners, Lux Capital, Draper Fisher Jurvetson, and Epic Ventures.
"The decision to form a new company is intended to accelerate the adoption of MRAM," Lisa Su, senior vice president and chief technology officer for Freescale Semiconductor, said in a statement.
"Current Freescale MRAM products have strong traction in the market," Steve Socolof, managing partner of New Venture Partners, said in a statement.
As part of the agreement, EverSpin Technologies will take ownership of the MRAM manufacturing assets and will be based in Chandler, Ariz.
EverSpin will continue to supply products to Freescale's existing standalone MRAM customers. In addition, EverSpin will be a supplier to Freescale of MRAM technology for use in Freescale's embedded products.
It's been a long haul for phase change memory, but the goal is in sight.
Numonyx, the memory joint venture between STMicroelectronics and Intel, is already shipping samples of phase change memory (PCM) chips to customers and will start shipping PCM chips commercially later this year, CEO Brian Harrison said at a press conference Monday.
"We expect to bring it to market this year and generate some revenue," Harrison said. "It is one to two years before it becomes widely commercially available."
Hearing a CEO talk about existing samples and near-term commercial shipments is a big deal for PCM. The technology has been stuck in the proverbial "a few years away" phase for a long time.
"It could be cheaper than flash within a couple of years," analyst Richard Doherty in said in 2001, predicting the technology might hit the market in 2003.
"We are making good progress," Stefan Lai, one of Intel's flash memory scientists, said in 2002.
Gordon Moore, co-founder of Intel and the man for whom Moore's Law was named, had an article in the September 28, 1970 issue of Electronics predicting that Ovonics Unified Memory, another name for the same type of memory, could hit the market by the end of that decade. (The same issue of Electronics also included this article: "The Big Gamble in Home Video Recorders.")
The delays have largely stemmed from two sources. First, it's not an easy technology to master. In phase change memory chips, a microscopic bit on a substrate gets heated up to between 150 degrees and 600 degrees Celsius. The substrate is made of the same stuff as CD disks. The heat melts the bit, which when cooled solidifies into one of two crystalline structures, depending on how fast the cooling takes place. The two different crystalline structures exhibit different levels of resistance to electrical current, and those levels of resistance in turn are then as ones or zeros by a computer. Data is born.
Both Intel and ST made a significant amount of progress in controlling the material in the past few years, Harrison said.
Size matters
Second, the makers of flash memory have continued to improve their technology. Back in 2001, some believed that flash would hit a wall at the 65-nanometer level of chip design. Then that got moved to 45 nanometers. Today, manufacturers mass-produce flash at 65 nanometers and have samples at 45 nanometers. Numonyx has samples of traditional NOR flash at 32 nanometers. Why switch when the existing technology continues to work?
Again, in the past few years, Intel and ST have made progress and figured out a way to produce PCM chips on the manufacturing lines developed for standard chips. That has eroded the barriers to bringing PCM out.
Although Philips, IBM, and others have made progress in PCM, only Samsung is close to coming out with chips commercially, Harrison said.
Why will the world want PCM? Performance, says Numonyx CTO Ed Doller. PCM chips can survive tens of millions of read-write cycles, he said, or far more than flash. Reading data to PCM chips takes 70 to 100 nanoseconds, or as fast as NOR flash. Data can be written to the chips at a rate of 1 megabyte a second, or equivalent of NAND flash. There is also no erase cycle, making it similar to DRAM.
In other words, you have the best attributes of three different types of memory--plus, PCM will potentially use far less power.
The cost premium is also coming down fast. By next year, Numonyx hopes to make PCM chips, using 45-nanometer processes, that can hold two bits of data per cell. If that's possible, those chips would compete in price with single-bit-per-cell NAND flash, the memory that's being put into solid-state drives today, said Doller.
But the most important thing is that scientists believe they will be able to increase the density of these chips comparatively easily. In the future, standard flash chips will need additional circuitry for error correction and other functions. Not so with PCM. The smaller the bits get, the less heat that will be required to flip them, Doller added.
"The most important thing is that it is scalable," Doller said.
Do you want to know the best thing about a notebook with a flash memory drive, rather than a conventional hard drive?
It's the silence.
The notebook I'm testing--a Dell Latitude D830 with a 64GB flash hard drive from Samsung--hasn't emitted a sound in three days. Flash drives, which store data in NAND flash memory, don't require motors or spinning platters. Thus, there are no whirring mechanical noises.
A Dell Latitude with a flash drive. You can definitely tell a difference in performance, but is it worth the $900 premium?
(Credit: Michael Kanellos/CNET News.com)Compare that with my T42 ThinkPad. It sounds like a guinea pig got trapped inside, particularly during the start-up phase. Vzoooot. Cronk, cronk, cronk. Zip, zip. (Pause.) Gurlagurlagurla...zweeee.
The lack of a mechanical hard drive also means lower power consumption and less heat. In turn that means the fan rarely, if ever, needs to kick into action. As I type, for instance, the notebook is running eight video streams-- two from CNN, two from CNET, two from MSN, a video on new bands on Crackle, and a pirated Led Zeppelin video on YouTube--and the fan won't trip over. The computer is running on battery power and the videos, with a few minor gulps, are all running smoothly.
If it did have a conventional hard drive, the fan would have flipped on, sapping battery power, and cranking out some white noise. I know that because I got the fans on my ThinkPad (as well as home notebook from Hewlett-Packard) to start in similar circumstances.
Is the quiet and extra battery life worth nearly a $900 premium? In a word, no, but you've got to look at the future. Although in the price stratosphere now, flash drives will start to compete more directly with drives over the next four years. Flash memory density continues to increase at a rapid pace, doubling almost every year, and large manufacturers like Samsung, Toshiba, SanDisk and Intel have or are opening factories geared at churning out flash. Taken together, this will lead to an easy availability of chips, better capabilities, and recurring price wars.
Flash prices dropped 50 percent in 2006. Prices rose a bit in 2007, but then dropped 50 percent from the fourth quarter of 2007 to the first quarter of 2008, says Jim Handy of Objective Analysis. Hardware manufacturers can now buy 1GB of flash for $3, he added.
When the premium becomes more acceptable, say $100, the category could take off. The lack of noise isn't one of the benefits I expected, but it was tangible. Listening to the drive on my IBM always prompts two thoughts. One, turning on a PC takes more time than it should and, two, this thing could collapse at any moment. To be honest, the ThinkPad has never imploded because of a hard drive problem, but the internal clanking makes it sound like it could. Silence gets rid of a minor aggravation.
Flash drives also boost performance, although less than I expected. The Dell with the flash drive takes anywhere from 1 to 6 seconds to come out of standby mode, depending on what types of applications were left on. Occasionally, the video that was playing when the computer was put into standby mode starts again. The ThinkPad takes at least 12 seconds.
Starting the Dell after a complete shutdown takes 19 seconds. It takes the ThinkPad 45 seconds to get to the part where I can enter a password. After the password is entered, it takes another 55 seconds before the computer is operational. Some of the slower times on the ThinkPad can be attributed to a slower processor and a more ornate start-up cycle. Even if you don't take that into account, the flash advantage only comes to seconds.
"If it takes one and a half minutes versus two minutes to boot up, are you going to care?" asked Handy.
Weirdly, shutting down both computers takes about the same amount of time. (Flash drives can take minutes off the launch of Outlook, but I couldn't test it because of network problems.)
The drive itself. Samsung puts its flash into a bay that would ordinarily accommodate a much larger 2.5-inch drive. As the market takes off, Samsung will chop down the size of this module.
(Credit: Michael Kanellos/CNET News.com)Battery power is tough to compare. The Dell has a larger battery pack than the ThinkPad. The ThinkPad is also much older. Still, the Dell with the flash drive seems to last longer than notebooks with standard drives. Fully charged, the battery says it will go five and a half hours, and the time remaining on the battery seems to follow the clock, i.e. an hour of battery time nearly comes to 60 minutes when few applications are on. With eight video streams, the five hours drops to two, but then kicks back up as windows are closed. Handy noted that a flash drive might consume a watt of power while a fast drive might consume 12 watts.
The drawback is the price. The same Latitude with an 80GB standard hard drive currently sells for $869 on Dell's site. Swapping the drive for a 64GB flash hard drive adds $899 to the price. The upgrade more than doubles the price of the notebook to $1,768 and slightly eliminates storage. That's down from the $920 price for the flash drive a few months ago, but out of reach of most buyers. (And it's worse at other vendors. Apple, which started offering flash drives after other PC makers, sells its 64GB flash drive upgrade for $999.)
Photos and high-definition video, among other applications, is also boosting the need for storage, which can favor hard drive makers. Samsung, among others, believes that corporate buyers only need around 64GB of storage, which will be economical to provide in flash in a few years. Consumer laptops, however, come with 160GB to 500GB of storage; 500GB of flash may not be reasonably affordable until 2012, and then consumers might need terabytes.
But if you can offload files onto a backup hard drive, flash could work for you.
Samsung is touting the reliability of solid-state drives, while citing an explosive market for the devices in server computers.
SSDs are based on flash memory chip technology and have no moving parts. Hard-disk drives (HDDs), in contrast, use read-write heads that hover over spinning platters to access and record data. With no moving parts, SSDs avoid both the risk of mechanical failure and the mechanical delays of HDDs. Therefore, SSDs are generally faster and more reliable. The catch is the cost: SSDs are currently much more expensive than HDDs.
Samsung 1.8-inch SSD
(Credit: Samsung)There are also concerns about wear. That is, flash has the potential to wear out after tens (or hundreds) of thousands of write cycles.
This characterization, however, is too simplistic, according to Michael Yang, flash marketing manager at Samsung. A flash device that is rated at 100,000 write cycles, for example, can write 100,000 times "to every single (memory) cell within the device," Yang said. In other words, the device doesn't write to the same cell over and over again but spreads out the writes over many different cells. This is achieved through "wear leveling," which is carried out by the SSD's controller, he said.
This would make it virtually impossible to wear out a flash chip. Yang said a pattern could be perpetually repeated in which a 64GB SSD is completely filled with data, erased, filled again, then erased again every hour of every day for years, and the user still wouldn't reach the theoretical write limit. He added that if a failure ever does occur, it will not occur in the flash chip itself but in the controller.
On another topic, Yang cited explosive demand in the enterprise server market that caught his company by surprise. "At first it just sounded like an interesting idea," he said. But then demand took off. As Yang explained, companies like Citibank and American Express peg server performance on IOPS or input/output operations per second. "HDDs do 120 to 150 IOPS. SSDs 10,000 to 30,000 IOPS." Because of this overwhelming speed advantage many large corporate customers are opting for SSDs, despite the significant price premium SSDs command compared with HDDs.
Regarding cost, Yang expects to see a 35 percent to 45 percent year-to-year drop in SSD prices. This will be a welcome relief since 64GB SSDs currently can add as much as $900 to the price of a notebook PC.
In the third quarter, Samsung is slated to bring out a 128GB SSD based on MLC (multi-level cell) technology--which uses multiple levels per cell to allow more bits to be stored. But the company sees even larger-capacity SSDs, ranging all the way up to 250GB, possibly before the end of the year.
The company is also working with notebook PC makers to design ultrathin notebooks with SSDs that can fit into potentially even thinner designs than the 0.76-inch thick MacBook Air, which uses SSD.
After using the solid-state-drive version of the MacBook Air for about 10 days, the notebook's potential is what sticks with me the most. The seminal construction and the influence this will have on future designs is what sets the Air apart.
Note: This is not a CNET review. The Apple MacBook Air CNET review is here. What follows is a brief personal observation, not a review.
In day-to-day use, I am impressed by the Air's boot times (under 30 seconds), resume times (instantly from sleep mode), and lack of hard-drive "thrashing" that occurs invariably on my HP laptop when running many applications (including development environments) over a period of days. Admittedly, none of these three are mind-blowingly better than my HP (Core 2 Duo, 3GB of memory, 7200-rpm hard-disk drive) but they are a big enough improvement to make a difference.
MacBook Air
(Credit: Apple Computer)
MacBook Air solid state drive
(Credit: Apple)As to benchmarks, I would concur with the benchmarks done at Bare Feats. Their conclusion: "The MacBook Air's 64GB [SSD] excels in small random reads and writes. That explains why it boots so fast, wakes so fast, and launches apps so quickly...When it comes to sequential READS, it beats the HDD significantly in medium to large transfers...The weakness with the SSD lies in the sequential write speed." Subjective use bears out the fast read times. But, to be honest, I've never been able to notice any difference between my HP and the Air in write speed.
The main point of this post, however, is what the MacBook Air augurs. The Air is no doubt the first of many svelte SSD-based notebooks to come from a host of manufacturers. And solid-state drives will only get cheaper, bigger (in capacity), and faster in the coming years. I believe Intel when it says: "The interface sequential performance for SSDs can be designed so that the only limitation comes from the selected storage interface (SATA 1.5 or 3.0Gb, USB 2.0 400MB/s, or SAS 3.0Gb)." In other words--as Intel goes on to say--SSDs can saturate the read and write bandwidth of the interface, which hard disks cannot necessarily do.
Needless to say, the design of the Air is irresistible. Its basic concept--a relatively high-performance notebook PC in an incredibly thin and lightweight package--will be copied by all the major notebook suppliers. Even with the Air's well-publicized shortcomings (which I won't repeat here), that's a good thing.
In the wake of a series of technical announcements from flash memory supplier SanDisk, larger-capacity solid-state drives are on the way.
SanDisk 72GB solid state drive
(Credit: SanDisk)Flash memory is gaining as a replacement for hard drives in ultra-thin, ultra-small notebooks such as the MacBook Air and Asus Eee PC. Why? Flash uses less power, generates less heat, and has faster access times than hard drives. The Air, for example, offers a 64GB flash-based SSD as an option while the Eee PC is sold standard with flash storage.
There is a big catch, though. High-capacity SSDs are expensive. Prohibitively so. The flash drive in the pricier $3,098 Air is the main culprit in the gaping $1,300 price difference with the lower-cost hard-drive model ($1,799).
Update: Historically, flash memory has had limited write cycles. That is, flash can eventually "wear out" after hundreds of thousands of write cycles--though firmware that spreads the writes over different sectors can extend the write cycles. It remains to be seen if this is an issue with SSDs used in the newest notebooks such as the Air.
The low power and high speed, however, make a flash drive almost irresistible for some users. A SanDisk SSD 1.8-inch drive achieves a sustained read rate of 66MB/sec and a random read rate of over 7,000 inputs/outputs per second for a 512-byte transfer, many times the speed of a hard drive--which must move an arm across a spinning platter to find data, the so-called seek time of a hard drive.
SanDisk will not discuss future pricing but as larger-capacity SSDs hit the market, prices are certain to fall. And eventually these will be steep price drops. For example, an 8GB SanDisk flash card now sells for about $80 at resellers. A few years ago consumers would have paid this much (or more) for a 1GB drive. (And a 1GB card was originally priced at $500 in 2004!)
SanDisk and Toshiba will start making flash memory on a new 43-nanometer manufacturing process that will result in SSDs later this year with capacities that should approach those of today's mainstream 2.5-inch hard drives, ranging between 120GB and 160GB.
The two companies recently achieved 32-gigabit (Gb) density, according to Khandker N. Quader, SanDisk's senior vice president of flash memory design and product development. The 32Gb die combined with multilevel cell (MLC) technology--which uses multiple levels per cell to allow more bits to be stored--"doubles the SSD capacity points," Quader said in a written response to questions.
Flash based on "X3" technology is another new development, Quader said. "This is an important milestone (and) allows us to do 3bits/cell as opposed to 2bits/cell thereby providing improved manufacturing efficiency," he said. "So a combination of technology scaling (i.e., 56nm to 43nm) and the bit scaling (i.e. 2bits/cell to 3bits/cell) is extremely powerful for manufacturing efficiency and for increasing capacities of flash memories."
But there are challenges. Moving to X3 can affect performance. "One very important point to take into consideration is that X3 is not a simple memory to manage," Quader said. "This is the first generation X3. We expect this to evolve in 2008."
SanDisk has also developed a 43nm 16Gb MLC for MicroSD, according to Quader. MicroSD is a tiny flash chip used in mobile phones. The new technology will double the capacity of current 8GB MicroSD, he said.
(Credit:
Kingston)
If you own a digital SLR camera or some other device that uses CompactFlash media, now's your chance to stock up on storage: Adorama has a 4GB Kingston CF card for $0 after a $40 mail-in rebate. Shipping runs $5.
Yeah, there's a rebate, but at least we're talking quality media here: Kingston is a top brand, and the company backs the cards with a lifetime warranty. Plus, the rebate itself is through Kingston, not Adorama, so it's probably a safe bet. If you're interested, don't wait: The rebate deal expires Friday (February 8), but I'll be surprised if the inventory lasts the day.
(Via Gizmodo)
Financing has been cut by about half for a partnership by Intel, ST Microelectronics, and Francisco Partners to launch a flash memory company called Numonyx, the companies said Wednesday. In addition, the company, called Numonyx, won't be established until early 2008, under a revised schedule.
Initially, Numonyx was to have received up to $1.55 billion in debt financing. The companies have revised financing terms so Numonyx now has a $650 million loan and $100 million revolving credit facility, Intel said in a regulatory filing with the Securities and Exchange Commission.
STMicroelectronics added in a statement that the companies obtained the new financing after "significant turmoil in the debt capital markets."
The companies had a December 22 deadline to establish Numonyx but have agreed to an extension to March 28, the companies said.
The partners still intend for Numonyx to "hit the ground running" with patents, a independent work force, and well-equipped manufacturing facilities, STMicroelectronics said. "Based on the finalized financing structure, at closing Numonyx is expected to have a similar level of net cash, with lower indebtedness, than originally anticipated," the company added.
Flash memory endows everything from portable media players to high-end laptop computers with data storage space, and its use is on the rise as more devices either have it built in or come with slots that accommodate plug-in flash cards.
CHIBA, Japan--BiCS. It's the acronym that could extend Moore's Law.
BiCS, which stands for Bit Cost Memory, is a three-dimensional flash memory chip developed by Toshiba in which transistors can be stacked vertically. Stacking vertically, ideally, will allow engineers to continue to add more transistors to a chip at a steady pace, which in turn means continual, steady improvement in electronics. Cost goes down, performance goes up, and everyone can continue to sell new products to willing customers.
Yellow is silicon and green is the gate in this BiCS model of stacked transistors.
(Credit: Michael Kanellos/CNET News.com)The company has created working samples and discussed the technology at academic conferences, but is showing the concept for the first time to the broader public at Ceatec Japan 2007, the tech trade show taking place here this week.
The key is that the chip is rewritable: data can be inserted and erased, as it can on regular flash memory chips. Matrix Semiconductor, which was bought by SanDisk in 2005, has a 3D chip, but the memory cells aren't rewritable. Whatever data is inserted the first time stays there forever.
The model pictured here helps explain how it works. The green layers are silicon gates. The empty spaces are sources and drains (the output terminals). The presence or absence of electrons going from the source to the drain are registered as ones and zeros and form the basis of computer data.
Those long, thin yellow poles are silicon piers. The piers control the flow of electrons. In a standard transistor, the surface area that connects the gate (the input terminal) and the silicon (which controls the flow of electrons) is relatively limited. Here, the entire circumference of the junction between the pier and the gate is used, increasing the surface area that connects the gate and the silicon and thereby improving performance.
The idea is similar to the tri-gate transistor and fin-fet transistors developed in labs by, respectively, Intel and IBM.
The BiCS prototype made by Toshiba.
(Credit: Michael Kanellos/CNET News.com)Toshiba has made samples on the 90-nanometer process.
And what else did Toshiba, which probably had the most comprehensive booth at the show, show off? The SpursEngine, a chip based on the Cell processor architecture.
These are smaller versions of the chips found inside the PlayStation 3. Rather than having eight identical cores for processing data streams, the SpursEngine has four. The idea behind the chip is that it can serve as a co-processor inside PCs, accelerating graphics, letting the computer conduct searches via images in pictures, etc.
Toshiba also showed off a working mini-TV with an integrated fuel cell. The TV operates 10 hours on a dose of methanol. In the past, the fuel cell has been an add-on appendage.
The company has committed to coming out with a fuel-cell-based product. The first one may come in the next year or two, a company spokesman said.
