When it comes to hard drives and solid state (flash) memory, can you see the future? I think the future is cooperative and collaborative; in other words, we’re going to move beyond the past competition between HDD and SSD to a more cooperative and collaborative environment. The reason for this is simple—people have a range of storage needs, and different storage needs create different requirements. The digital lifestyle has created a greater demand for storage devices in general as we desire to move information or content from our offices to our homes, to our cars, and to our handheld devices.

Some of these devices require storage that exhibits extremely fast input /output times (i.e. nanoseconds) to store and retrieve information but needs only relatively small capacities, and price and volatility are also less of an issue. Examples include DRAM for PCs. Other devices' requirements call for huge storage capacities, where access speeds are of the order of milliseconds to store and retrieve information, but where price, reliability, and volatility are key. Examples include hard disk drives for PCs, home video recorders, servers, back-up devices and even tape storage.

Other devices' storage needs lie in-between these two sets of extreme requirements. Flash memory has a lot going for it—it can be small, lightweight, consume less power than hard disk drives and its data can be read very fast....although write speeds are often slower than those of hard drives. This is a great form of storage for cameras, MP3 players, thumb drives, etc. But on a per-GByte basis, flash memory is much more expensive than hard drives, costing up to 8 times more on the wholesale level. This higher price is also reflected on the retail level—as I write this, Dell has introduced an option for a 1.8” 32GB solid state drive (SSD) from SanDisk in the Latitude D420 ultra-mobile and D620 ATG semi-rugged notebooks. The added price over the 30 GB HDD is $549!

There will be some people who are willing to pay more for less capacity just to enable decreased boot time by up to 34 percent, according to Dell, versus a standard hard drive. Conversely, there are many people who would prefer an iPod-type device with as much storage capacity as possible to carry large photo albums, videos, and music, and who don’t want to pay a premium for the device. For these requirements, a hard drive-enabled device is very desirable. According to most analysts, hard drives are expected to retain the key price advantage over flash memory for the foreseeable future.Hard drives are also expected to retain an advantage in storage capacity measured in TBytes (a terabyte equals 1000 GBytes).

Flash memory technology will continue to improve as well. Current flash memory (NOR and NAND – both SLC and MLC) is benefiting from semiconductor fabrication techniques that yield geometries and line widths down to about 50 nanometers in size. These critical dimensions will continue to shrink over time, extended by changes in materials, processing and structures. Ron Dennison, Principal Consultant with Research Development Consultants, Inc, told me in a recent conversation that if new technologies are required, there are a number of follow-on solid state memory candidates (Phase Change, Carbon Nano-Tubes, R-RAM, Spin-RAM, etc.) waiting in the wings with the projection of extension to perhaps 5 nm. Every one of these technologies will require a significant amount of time to mature into products due to the nature of the semiconductor process business.

Combining flash memory's features with a hard disk drive into one package, called a hybrid drive, makes a lot of sense for some applications, as it captures a broader set of key needs, and will likely find its place in the overall storage hierarchy. More generally, hard drives and flash memory can be complementary rather than “cut-throat” competitive. As more and more of us carry around increasing amounts of digital content, we store that content on hard drives. The hard drive remains the primary storage option even as we use flash memory for more portable devices. It’s been estimated that it takes six hard drive-based storage systems to deliver content electronically to a hand-held device. So looking forward, I see a continued need for a synergistic approach to hard drives and solid state storage.

Joel Weiss
IDEMA