Two Opinions on Future of HDD Vs. Flash on Mobile Devices: Tom and Gerry …

J. Gerry Purdy, Ph.D., Principal Analyst with MobileTrax, had an interesting dialog with Tom Coughlin of Coughlin Associates. Tom is an analyst that covers the storage market including mobile. They were discussing the future of mobile storage. Gerry asked Tom if he felt that all mobile devices would become flash-based and no longer use hard disk drives (HDD).

Overall, Tom believes that in five years (2016) the average notebook PCs will have around 4TB of storage made up of 3.5TB of HDD and 500GB of flash used as a front end cache. And, the average SmartPhone will have 250GB of flash and the average tablet will have 500GB of flash storage.

To put this in perspective, Apple’s largest storage capacity today in the iPhone is 64GB, and we can expect to see an increase of about 10x over the next five years. Future HDDs will include flash on the front end to quickly process requests for reading and writing as a ‘front end cache’ to the larger HDD storage. The disk drive will sit behind the flash and store huge amounts of data.

There will also be a large increase in the availability of external or removable storage with SD and microSD cards increasing from 32GB today to over 300GB and external hard drives increasing to 4 to 6TB (2.5” drives) and over 10TB with 3.5” drives.

Tom and Gerry both believe that while some information like popular songs may reside in the cloud and simply be streamed to the mobile device, users will always want to have and keep a copy of their information and use it on all of their mobile devices. This makes services such as Unifi (RealNetworks) and SugarSync become more important to keep the user’s content available across all of their mobile devices.

They also believe that user generated HD video (and eventually Ultra HD video that includes 3D) will be the primary driver for the higher capacity local storage requirements with photos, music and productivity files falling in behind. One thing is certain: future mobile devices are going to have more storage – a lot more – than in the past.

Here is the exchange of emails
that Tom and Gerry had in December:

Gerry: After seeing the MacBook Air – sleek, thin and using all solid state flash storage, I wonder if we’ll see all notebooks using only solid state in 4-5 years. Thoughts?

Tom: It is likely that in five years, all notebook computers will have flash memory in them. But, it is also very likely that most notebook computers will also have HDDs. We believe that dual storage and hybrid storage solutions in notebooks will be the most popular type.

The rate of increase in flash capacity and the associated reduction in cost per GB might suggest that users will simply have enough storage and it will all be flash.

By the time most people can afford 1 TB of flash, they will likely be using 20 TB disk drives. HDD still provides a tremendous cost/GB advantage over flash and will for many years to come.

Are you saying that you feel that flash will remain a 20x price difference per GB? What about the concept of stacking or layering flash chips? SanDisk says it is going to use to put up to 10 layers vertically on a single flash chip.

I think what you’re implying is that notebooks will have very thin form factors with a combination of front-end cache with very fast flash (perhaps 100-500GB) and have a multi-TB HDD sitting behind it.

There are many technologies for both HDD and flash memory that will increase storage capacity. All of them are hard to do, and it is likely that both may develop more slowly than in the past – although this sort of prediction has proven wrong in the past. There are technologies for increasing HDD areal density and flash storage capacity (like the flash layer stacking) that will keep both technologies increasing capacity over time.

On the other hand, larger inexpensive storage in more things will probably encourage the development of applications that will use that storage, such as a move from today’s HD content to Ultra-HD (up to 8K X 4K pixel video) and perhaps Ultra HD in stereo. Ultra HD will likely use hundreds of GB for an hour of content (and this is for the compressed distribution format). This could keep demand for healthy amounts of local storage for many users high.

Thus the best use of flash in some consumer and most computer applications is probably as another layer in the computer storage hierarchy to help deal improve the overall system performance, not to replace the mass storage.