Inside the MacBook Air: The solid-state drive option

by Jon L. Jacobi

January 24, 2008 —

When it comes to storage, the newly unveiled MacBook
Air offers an 80GB, 4,200-rpm Parallel ATA hard drive as part of its standard
configuration. However, that's not the only option -- would-be MacBook Air buyers
can also order the laptop with a 64GB solid-state drive (SSD).

The price for that downgrade in storage capacity: US$999 on top of the $1,799
asking price for the standard MacBook Air. So why would you pay so much more
for less?

Because, for some mobile users, solid-state storage is a compelling alternative
to traditional hard drives.

Think of SSD as a grown-up version of those flash memory sticks you slip into
your Mac's USB ports. Instead of storing data on spinning platters, as a standard
hard drive does, SSDs store data in solid-state memory--either NAND flash memory
or SDRAM. Increase that USB stick's capacity and add an ATA or SATA interface,
and you've got an SSD.

SSDs seem like the perfect mass storage devices for a notebook. They have no
moving parts, so they're less susceptible to damage from the shocks and jolts
of travel. SSDs can withstand 10 times as much impact as a standard hard drive.
They also deal well with vibration.

Then there's an SSD's parsimonious power consumption. Powered down, SSDs consume
virtually no juice -- somewhere around 0.05 watts. Even when operational, an
SSD draws only 1w or so -- about a third the consumption of a comparable hard
drive.

In terms of seek times and throughput, SSD performance is about equal to that
of a standard hard drive. But SSDs turn on instantly: They don't have to spin
up platters as hard drives do, so they reduce computer boot, restart, and wake-up
times substantially.

In addition to being sturdier, more power efficient, and faster than standard
hard drives, SSDs are also slightly lighter and can, if necessary, be molded
into different form factors to fit tight spaces. The circular platters of a
hard drive don't allow for that kind of design flexibility.

So what's the catch? As the cost of the MacBook Air's storage option indicates,
SSDs are still extremely expensive. However, there's some good news -- the cost
of NAND memory is declining by about 40 percent per year. In other words, what
seems wildly expensive now may seem more reasonable in the not-too-distant future.

Macworld.com