Data Center Advisors

McBlu-ray

I have a soft spot for disruptive innovation or game-changing technology. I like to see the establishment tossed around and turned upside-down a bit. Not from an anarchist point-of-view, but from a change-is-good perspective. Of the disruptive attributes that we typically focus on in technology, cost reduction, performance, reliability and ease-of-use, aka, user friendly, cost and performance tend to be the easiest to measure and quantify, while reliability and ease-of-use are either long term observations or based on perception. Of course, the combination of these attributes are also important such as, reduced cost and high performance, high reliability and reduced cost. There are a number of other attributes that are usually considered, but are typically harder to measure. Let’s take optical storage as an example. I’ve blogged about optical a little bit previously and I want to revisit this.

Specifically, is Blu-ray a revolutionary technology? No, yes, well? No, it’s not disruptive to the data storage industry. It is a planned disruption to the content delivery industry. Well, a planned disruption is not what I was looking for. It is however, evolutionary. Meaning it is an enhancement to the existing optical data storage market. In fact, there are enhancements to Blu-ray technology that will bridge the DVD and Blu-ray standards together, sort of a transitional technology phase. As an example, JVC can put DVD and Blu-ray formatted data on the same disc even on the same side on different layers. However, all this means is that content can be stored and played on two types of players from the same disc.

However, I will concede that there are some exciting enhancements and extensions being researched and proposed to the Blu-ray standard. Some of the ones that I’m interested in and are related, and possibly relevant, to the data storage industry are in capacity increases. Of course Hitachi research is heavily involved in increasing the usable capacity of Blu-ray. Hitachi announced an increase to 100 GB on a single Blu-ray disc using 4 layers of 25 GB per layer some time ago. This can be done without changing any hardware and only requires a firmware update to the Blu-ray reader and the first product should be available to the market later this year. 200 GB on a single disc is planned to be announced this year, meaning product possibly in 18 months(?).

Other Japanese companies have or are announcing plans to increase usable storage capacity in the future. Sony and Panasonic worked together and announced in January 2010 the increase in layer capacity from 25 GB per layer to 35.4 GB per layer and only requires a firmware upgrade to existing players to use the new density. In December 2008, Pioneer announced a 400 GB disc using 16 layers and a 500 GB disc using 20 layers, and usable with only a firmware upgrade. 1 TB on a single Blu-ray disc by 2013 is possible. When I say announced, this doesn’t actually mean generally available. It typically means that the R&D labs have figured out a way of getting to these capacities then told us. Product will not be available for some time.

There are a number of problems here with these capacities. If you shop around the internet a bit, you can find a dual layer 50 GB rewritable Blu-ray disc for about $24 per disc. That’s about $0.46/GB for a consumer grade disc. Not that great of a bargain when you compare it to a consumer class 1 TB hard disk drive today. At this point, I’m not including power costs, portability, or longevity characteristics.

Also, the write speeds for a 50 GB dual layer Blu-ray disc is 90 minutes at 2x speed. That works out to about 9 MB/s. A 12x speed writer can decrease this time to 15 minutes at a transfer rate of 54 MB/s, but the cost of that media will almost double. At this point, when comparing media capacity, cost and write speed, tape still seems to be a clear choice. Again, I’m not including the longevity characteristics here and the cost of re-mastering media. I’m saving this for a later discussion.

The write speeds of Blu-ray may make this a challenge for large archiving solutions with high ingestion rate requirements. However, there is an advantage to Blu-ray high capacity discs in the inactive archive arena. Given a disc with 20 layers, like the 500 GB statement by Sony and Panasonic, means a seek latency that is much lower on average than LTO tape. In this case, a laser focus to a 25 GB (or future 35.4 GB) layer then seek to the object or file requested. Doing this over several Blu-ray drives allows for a relatively responsive archive assuming the data stored there is predetermined for this use.

So, I’ve stated this in previous blogs that optical storage always seems to be behind when compared to the storage industry’s requirements. Of course the primary use case for Blu-ray is not necessarily data storage, it’s primarily for content delivery or at least that’s its biggest market. With the demise of inPhase and a huge setback for holographic storage, Blu-ray and its coming enhancements will keep this technology rolling for quite some time. But will it compete with the hard disk market? By the time the media is developed, tested and announced as “look what we can do!” for the 1 TB Blu-ray disc, the magnetic hard disk industry could be announcing the end-of-life for its 4 TB drives.