In consumer and professional fields the demand for storage continues to skyrocket, and new research carried out by Understanding & Solutions looks at the removable storage market, the future opportunities and the challenges ahead for the competing formats.

In the consumer arena, optical media solutions such as traditional CD and DVD are becoming unsuitable for high volume storage requirements, as capacities fall short of many users’ requirements. “We’re already seeing a migration from optical disc to hard disk devices such as PVRs and Media Centre PCs, with DVD recording becoming a more occasional function.” says David Millar, Business Director of Disc Pressing and Storage Media at Understanding & Solutions. “However, these devices commonly use fixed hard drives which have a finite storage capacity. There’s still a need for users to archive the content, which requires that it be copied to a removable medium, which, ironically, tends to be optical disc.”

But optical discs are evolving, and third generation discs, based on blue laser technologies, can already store up to 50GB, with future potential to provide a 200GB disc to consumer markets. In the mid-term, this will be more than adequate for consumer use.

However, professional storage capacity needs are well in excess of 200GB, and to a great extent enterprises continue to rely on tape for high volume data storage and archiving. “Tape is cost-effective but its access time is slow when compared with optical disc,” says David Millar. “This issue of access times is opening the door for 4th generation optical media formats, which are being developed with a one terabyte-per-disc target capacity.”

“Price reductions and end-user perceptions of the reliability of hard disk have also improved significantly,” continues David Millar, “with end-users now opting to store greater levels of data on these devices. Disk to disk backup is becoming increasingly common, either to ‘mirror’ files at a different location or through the growing trend – particularly amongst SMEs – of using third party off-site storage services.”

The blue laser optical disc could possibly be the last generation of physical media, but it will have a product life cycle of at least ten years. Looking further forward, according to Understanding & Solutions, the long term trend shows a move towards networked delivery of content on demand, with local storage needs being fulfilled using HDD-based home servers.

In addition to Blu-ray Disc and HD DVD, there are a number of next generation optical disc technologies currently in development and production, which include UDO, Holographic Data Storage, Super-RENS, Multilayer discs and even biological discs using bacteria, enzymes, proteins and other biological-based solutions.

“In terms of the future optical disc market, long term success will only be possible by increasing the capacity per layer as well as the number of layers available,” says Bill Foster, Senior Technology Consultant at Understanding & Solutions. “This is the only way it will be able to compete as a sustainable format. To increase optical disc capacity beyond 35GB per layer using conventional replicated pit structures is going to require lasers with shorter wavelengths than the 405nm used today for Blu-ray, HD DVD and UDO, a further reduction in cover layer thickness beyond the 0.1mm employed by Blu-ray, and/or an optical pickup with a numerical aperture (NA) beyond Blu-ray’s 0.85.”

Though the battle between hard disk, optical disc and tape has run for decades, Flash memory has emerged over recent years as a worthy contender. Initially capacities were low and cost per megabyte very high, pricing it out of the marketplace, but this has changed. Price points for Flash have now dropped to a level which is allowing PC manufacturers to offer products with hybrid Flash/hard disk drives, or in some cases Flash-only drives.

“One impediment to the future roadmap of Flash memory cards is the 32GB milestone,” says Bill Foster, “which will require another change to the file format for cards using the FAT32 file system. What this new file format will be has yet to be decided, but the NT File System is believed to be under consideration. Once a new file format is agreed upon and the technology is in mass production, this will serve to significantly extend the Flash lifecycle.”

Looking to the future, the consumer market will be driven by subscription service providers (cable, satellite and IPTV), increasing the household penetration of set top boxes which provide HDD storage. The main STB will take on a secondary role as a networked media centre, providing easier access to online movies and other content. Content on physical media will be ‘ingested’ into the media centre and accessed alongside electronically delivered content.

The ability to store content electronically will drive the growth of higher capacity hard drive based servers, whilst at the same time causing a downturn in the demand for removable recordable media; although, because HDD capacity is finite, and off-site storage is not always the optimal solution, some removable media will still be required for archiving purposes, particularly where large numbers of ‘download to own’ movies have been purchased. This removable media is likely to be next generation optical disc.

Story filed 18.04.07