Will flash EVER replace disk?
How about never - is never good for you? As a long-time fan of flash (NAND) storage - and a flash notebook long-ago user - I've been repeatedly surprised at how the hype for flash drives and the reality have diverged (see Hybrid drives: not so fast, Flash drives: your mileage WILL vary, and Power, notebooks and solid state disk).
I bought into the hype initially, but as the hype and the facts have diverged, I've gone with the facts. Despite its well-known liberal bias, engaging with reality has its advantages. If only more people would.
Update: The "reality has a liberal bias" comment was a crib from Stephen Colbert of Comedy Central's The Colbert Report, which I think is funny in a technology context because technology isn't "liberal" or "conservative," it just is. However, being "data-driven" is a new - ~400 years old - and "liberal" concept that many are still suspicious of, thus the humor in Colbert's remark. End update.
The (disk) empire strikes back I'm here at DISKCON 2007 USA in Silicon Valley. The tension between the disk folks and the flash folks has been the subject of some forced humor. If somebody announced the intention to take 25% of your income, how funny would YOU be?
The most outspoken disk defender is Rich Rutledge, SVP at Western Digital, the 2nd largest disk manufacturer. His argument, stripped to the essentials, is that flash will *never* deliver on the hype, because it can't. Rich's basic point is that most of flash's advantages are illusory:
- Power: disks are pretty efficient, and today's notebooks have a lot of power-hogging systems (Wi-fi, Bluetooth, display, dual-core processors, GB of RAM and graphics co-processors) so the additional battery life that flash can deliver is less than 6%.
- Boot times: cold boot not all that much faster - 8-10% - and the fastest boot times in Vista come from Vista's Sleep mode, which uses the battery to keep your data live in RAM, the fastest mass storage in your notebook.
- Size & weight: important in handheld devices, but notebook size and weight are dominated by keyboard and screen requirements, not the extra grams of a disk drive. Flash in small ultra-light notebooks? Sure. In a 17" behemoth? Much less likely.
- Performance: flash, is a top fuel unlimited dragster - fast in the quarter mile, but no good on curves. That is, the flash drive's massive advantage in small random read speed is lost in the real world where small random writes and large sequential reads and writes drown out the flash drive's one big performance advantage.
Why the hype? I want to believe that flash drives will be better. But since they aren't now, why the hype?
One of the flash presenters was surprisingly forthright. He said that the current flash-based consumer product sales are heavily weighted towards the holiday season. The several billion dollars a flash fab costs means keeping the fab running flat out is a very Good Thing. With the current product mix they can't.
What to do? New products that aren't seasonal.
The Storage Bits take Rich makes some good points, but I'm not ready to write flash off. Let's give the engineers a chance to do their magic. But I'm far from convinced that the flash vendors have the Mojo to pull off what they've promised. Enough hype, let's get some results.
Comments welcome, as always.