Feeds

Flash and the five-minute rule

NAND then there was disruption

Securing Web Applications Made Simple and Scalable

Why Now?

Why is this happening now? Dale said you can put flash chips together to get capacity not too expensive compared to disk. Secondly, there is a ton of innovation being poured into MLC NAND, which is cheaper than SLC. Thirdly, array vendors getting much better at tiering and so you can put flash drives as a tier zero in there.

He said, all things considered, "We're at the front end of a big discontinuity," and, getting back to the five-minute rule and comparing DRAM and flash, not DRAM and disk, "You can keep five hours worth of data in flash cache ahead of disk now." When treating flash as backing store for DRAM, the five-minute rule holds at a 6KB page size for DRAM.

The result of this is that you won't buy as much DRAM as you do do now. Also the random working set in DRAM can be reduced from one hour to five minutes.

Enterprise Arrays

Enterprise arrays are affected by this just like host servers. Dale said the application area opportunities include intense random reads, sequential read after random write and low read latency, enabling memory resident apps.

He identified three use cases: flash now showing up as tier zero in arrays, read caching in the controller with the hot working set always there, and having SSD cache in the network. Think Avere.

The flash invasion of arrays means you will buy fewer disks. It's inevitable and it's only the beginning. He thought it will affect vendors more than customers.

Ironically NetApp only has one of these use cases in its product line - caching in the controller with its PAM card - it has yet to introduce tier zero flash into its arrays.

His presentation finished up with a prediction that we will see the introduction of a flash-based Storage Class Memory sitting between DRAM and disk arrays by 2013. He showed a slide predicting that MLC NAND would meet enterprise HDD on cost/GB around 2012-2013. His penultimate slide said:

Over the next five years solid state technologies will have a profound impact on enterprise storage ... The architectural balance of memory, cache and persistent storage will change. Today's solid state implementations in enterprise storage demonstrate these changes. It's only the beginning.

There is a storage discontinuity between DRAM and hard drives and flash is going to fill it - that is now beginning to look like a certainty.

Bootnote

David Dale's presentation is on an SNIA website for the London event. If you are in the SNIA you can request the location and password by emailing Paul dot Trowbridge at Evito dot com. If you are not in the SNIA then we guess you'd better join and then send the email to Paul. ®

The Essential Guide to IT Transformation

More from The Register

next story
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
EU's top data cops to meet Google, Microsoft et al over 'right to be forgotten'
Plan to hammer out 'coherent' guidelines. Good luck chaps!
US judge: YES, cops or feds so can slurp an ENTIRE Gmail account
Crooks don't have folders labelled 'drug records', opines NY beak
FLAPE – the next BIG THING in storage
Find cold data with flash, transmit it from tape
Seagate chances ARM with NAS boxes for the SOHO crowd
There's an Atom-powered offering, too
Intel teaches Oracle how to become the latest and greatest Xeon Whisperer
E7-8895 v2 chips are best of the bunch, and with firmware-unlocked speed control
prev story

Whitepapers

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.
Mobile application security vulnerability report
The alarming realities regarding the sheer number of applications vulnerable to attack, and the most common and easily addressable vulnerability errors.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.