This type of capacity, bandwidth, and latency suit the Violin
for high-performance imaging, large-scale caches, real-time data
acquisition, databases, design automation, and scientific computing.
The 1010 connects to a host computer via a 10- or 20-Gbit/s PCI
Express interface, providing latencies as low as 3 µs. And at more
than 1 Gbyte of DRAM or 10 Gbytes of flash per watt, Violin presents
the ideal solution for data centers vying to be more green.
Small-form-factor solid-state drives (SSDs) are making more
and more inroads into the memory market. SMART Modular
Technologies’ recent XceedLite, a PATA 1.8-in. SSD, features
what the company claims is the industry’s lowest power consumption
(Fig. 3). The device draws 80 mA while reading, 70 mA current
while writing, and 9 mA in passive mode during operation in
the 3.3- to 5-V range.
In addition, the XceedLite supports 8/16-bit data register
transfers, PIO Mode 6, multiword DMA Mode 4, and Ultra
DMA Mode 5. The SLC NAND flash device, which has an
optional ruggedized enclosure, was designed for industrial-grade
specifications as well as tablet PCs, ruggedized notebooks, and
industrial and embedded designs. As with most SSD devices, it
includes on-board error correction and dynamic wear-leveling.
Yet these examples illustrate one of the problems with today’s
storage market. The storage medium and bus technology options
are endless, especially compared to yesterday’s choice of single-sided
versus double-sided floppy disks. Thus, further analysis may be
needed to discover which technology best suits your next design.
COST OF OWNERSHIP
When contemplating a storage solution for a particular application,
consider the end users and how they will be using your product, its
lifecycle, and the conditions under which it must operate during its
lifespan. And remember, the best solution may not always have the
cheapest up-front cost.
Take magnetic versus flash hard-disk drives as an example (Fig.
4). Under most circumstances where durability and reliability are
critical, flash wins every time. But after you get past a few gigabytes,
cost becomes a huge issue. This is where cost of ownership comes
into play. Solid-state drives may carry a heavier pricetag up front vs.
their magnetic counterparts, but what about their cost to the user
over the product’s lifespan?
Cost-of-ownership studies
should be done with every
new design as part of the overall risk assessment. If the new design were a laptop computer, cost of
ownership should include the purchase price and the cost to the IT
department to load the laptop with the proper software, deploy the
laptop, and provide initial training.
The cost of using the laptop then must be considered over time,
which gets more difficult when adding in boot time, application
launch time, downtime due to software/hardware failures, etc.
Next, consider the support and maintenance cost over time. Lastly,
when it’s time for a platform upgrade, costs must be considered.
With respect to cost of ownership, we can compare the cost of
owning a solid-state solution to the cost of a magnetic hard disk
over time to determine if a solid-state drive would be worth the
extra bucks. Solid-state drives offer improved reliability, improved
read performance, and lower power consumption, but at a greater
unit cost and a generally more limited capacity.2
"The product qualification process can be a challenging one,
especially for applications requiring long product lifecycles," says
Gary Drossel, SiliconSystems' VP of product planning. "Since
product life can be tied closely to the storage solution used, establishing
the projected life of a product’s storage system solution
under various application-specific usage models provides a critical—
though previously unavailable—indicator of storage system
performance over time. Advanced storage technology that
constantly monitors and reports the exact amount of a storage
system’s remaining usable life has become crucial to detect issues
early enough to actually do something about them." (See “Improve
Product Qualification Accuracy With Advanced Solid-State Storage
Usage SMART Monitoring Technology,” ED Online 18632.)
After assessing the risks and considering tradeoffs with the
cost of ownership, the next question to ask is: Will a customer
pay more for a more robust solution? The answer depends on how
customers plan to use the device. When all else fails, it might come
down to what we’ll call the “coolness factor.”
MY DEVICE IS “COOLER” THAN YOURS!
The “coolness factor” often gets overlooked when we discuss end
products. With a cell phone, coolness comes from the look and
feel of both the phone and GUI, as well as from slick features that
would make other users jealous, like navigation and television.
But how do you measure the coolness of a storage device? A few
factors come to mind: boot/recovery time (as compared to other solutions), noise factor, vibration, and heat. Flash hard drives beat
magnetic hard drives outright in each of these categories. After all,
flash can provide “instant on” capabilities with less complex operating
systems and will “boot” noticeably faster for bulkier ones.
Then there’s the noise. Magnetic drives are noisy little buggers,
which can be quite annoying. This annoyance gets compounded
when you’re using an operating system that likes to pound on the
drive every now and then for no apparent reason.
Magnetic drives also tend to give off a lot of heat. If you use a
laptop, this too can be annoying, especially when the weather (or
office) is warm. Speaking of laptops, don’t forget those precious
few seconds lost at various moments throughout the day waiting
for the hard drive to perform some little task like, say, opening a
folder. Tick, tick, tick... there goes your life.
So is a device that costs more but is “cooler” than other products
worth more money to the end user? Just ask Apple about its iPod,
iPhone, and MacBook Air sales, and you ought to get an idea.
References
1. Tales from the Lunar Module Guidance Computer, NASA Office of Logic Design,
April 20, 2005.
2. Evaluating the SSD Total Cost of Ownership white paper, Jeff Janukowicz and Dave
Reinsel, 2007, IDC, www.idc.com