Solid-State or Hard Disk Storage?
Deploying the right amount of RAM can lead to both improved performance and decreased battery life. However, replacing a magnetic hard drive with a flash-memory-based SSD drive is a "two-fer" gain that both increases performance and extends battery life. There are, however, other trade-offs to be aware of.
My test laptop had a 60GB hard drive that spins at 5,400 rpm. Note that this speed, while not as fast as most hard drives found on desktop computers, is by far the most common type of disk found on laptops, largely because faster hard drives demand more battery power.
In my tests, switching from a traditional 60GB hard drive to a 32GB Samsung flash drive boosted storage performance, or the notebook's ability to find and retrieve data, by 50% while using 38% less power.
All told, the system delivered an extra 20 or 25 minutes of battery life when using the flash drive than it did with a traditional mechanical hard drive. Overall system performance increased by 10%.
At a more micro level, another test, the HD Tach benchmark, found that the SSD drive read data 45% faster than the hard drive. In addition, the flash drive's random access time, which measures the lag the drive incurs to find the needed data, was just 0.3 milliseconds, a fraction of the hard drive's 17.9-millisecond access time.
Those performance results are not surprising, given that hard disk drives are largely mechanical, with spinning disks and read-write heads that locate information. In contrast, solid-state flash memory chips have no moving parts and can find and transfer data much more quickly than a hard drive's spinning disk. Another advantage is that SSD drives are nearly indestructible and are perfectly quiet.
In fact, the only time the hard drive excelled was in burst data transfers, in which, for brief periods, large amounts of data are transferred at once. The magnetic drive was more than twice as fast as the SSD at bursting data. This is a result of the hard drive using the newer SATA interface, which is capable of 150Mbit/sec. throughput and bursts of 600Mbit/sec. In contrast, the SSD uses the older IDE interface, which runs at a maximum of 133Mbit/sec.
A more serious trade-off of SSDs, however, is that they are currently very expensive. Our 32GB test unit, for instance, cost $520, compared with about $75 for a traditional hard drive. And these new drives don't have nearly as much available storage capacity as traditional hard drives -- for most users, 32GB is just not enough space, especially at the price. That's changing -- Samsung reportedly will introduce a 256GB SSD this fall -- but prices likely will remain very high.
Adding It Up
Overall, we were able to improve our test laptop's performance by more than 30% while extending battery life slightly by picking the right components.
There are, of course, some caveats for these results. These were not meant to be comprehensive tests using all possible configurations and all possible applications.
In the final analysis, we all use our notebooks differently -- tasks like checking e-mail and writing documents with Microsoft Word, for instance, are not as demanding as editing video or performing complicated simulations. As a result, the right notebook configuration for you will depend both on what you plan to use it for and the size of your budget.
Still, for general use with Windows XP, my tests found that the best balance between performance and battery life was to have 1.5GB or 2GB of system memory. If you're using Vista, which is more resource-intensive, start with at least 2GB and work up from there.
Also, flash storage drives provide better performance and longer battery life than traditional magnetic hard drives do. And, because they have no moving parts, they're more durable. However, they are expensive and currently offer limited storage capacity. That means most users will go with traditional hard drives -- until prices drop and capacities increase.
The bottom line: Many people believe that you can't have both better performance and longer battery life. My tests found that just isn't true. In fact, finding the configuration that provides the best performance often also provides optimal battery life.