Upgrade your laptop without going over the line

Buying a notebook computer can be an exercise in limitless possibilities, whether you're buying for yourself or for 250 users in your organization. That's because most laptop vendors offer a dizzying array of configurations.

Some people simplify matters by overspending, wagering that loading the laptop with unnecessary power is better than getting shortchanged on performance. Others underspend, assuming that it's better to save money than to pay for unneeded power.

Such uninformed decision-making, however, often leads to either underpowered or overpriced laptops. But who has time to test the major configuration choices to find out which offers the best balance of performance, price and battery life?

Well, I did.

To find today's notebook configuration sweet spot, I used a typical laptop to examine performance with six different levels of system memory, ranging from 512MB to 4GB. I also examined whether to use a traditional hard-disk drive (HDD) or a solid-state storage device (SSD) that uses flash memory.

I looked at the impact of these choices on both system performance and battery life.

Along the way, I learned several things about the trade-offs between performance, battery life and price. Here's what I discovered.

How much RAM is enough?

The first part of the laptop configuration conundrum is how much RAM to add to use. My tests found, not surprisingly, that adding more RAM leads to better performance. However, I also found the point at which adding RAM stops being cost effective and actually eats into the system's battery life.

Adding RAM is effective because it enables more of the system's operations to be done in the notebook's system memory. That, in turn, means less reliance on slower virtual memory, which uses the laptop's physical storage to simulate RAM when there is more data than the regular RAM can handle.

In my tests, filling the memory slots with 4GB increased memory performance -- how long it takes for data to go in and out of memory -- by about 7 per cent and increased overall system performance by 15 per cent compared with the test laptop's base configuration.

The biggest improvement, from a percentage point of view, occurred when increasing memory from 512MB to 1GB, but there was also a significant increase between 1GB and 1.5GB.

However, upgrading memory is effective only up to a point. That's because at some point the added memory isn't needed, and as a result, it sits idle and doesn't help with performance. That unneeded RAM does, however, draw power from the laptop's battery.

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Benchmark tests on our test Windows XP laptop found the cutoff point to be at about 1.5GB of RAM. After that, adding more RAM resulted in smaller and smaller performance boosts.

In fact, the last gigabyte of RAM added, which brought the total to 4GB, increased overall performance by less than 1 per cent and lowered battery life by 15 minutes. Most people will not find this to be an acceptable trade-off.

These tests were run on a Windows XP machine. Given the higher resource demands of Windows Vista, it is reasonable to assume that the peak benefit in terms of adding RAM to a Vista system would occur at about 2GB.

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 per cent while using 38 per cent 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 per cent.

At a more micro level, another test, the HD Tach benchmark, found that the SSD drive read data 45 per cent 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 US$520, compared with about US$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.

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Adding it up

Overall, we were able to improve our test laptop's performance by more than 30 per cent 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.

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How we tested

To find out how system memory and hard-drive choices affect performance and battery life, I used a Fujitsu LifeBook T2010 system. The 3.6-pound tablet has a 1.2-GHz Intel Core 2 Duo processor and uses Microsoft's Windows XP Tablet Edition, which is a variation of XP Professional.

I used Windows XP instead of Windows Vista because XP is still the most common operating system on laptops even though Microsoft is phasing it out. And, from a more practical point of view, not all the system benchmark tests I used support Vista. As I mentioned above, Vista's system requirements are higher than those of XP, so if you buy a Vista laptop, plan accordingly.

I used 512MB, 1GB and 2GB RAM modules to vary the amount of system memory from 512MB to 4GB. I tested with both a 60GB Fujitsu MHW2060 hard drive, which has a single disk that spins at 5,400 rpm, and a Samsung 32GB SSD storage module.

The variable I didn't control was graphics memory. The T2010 uses an Intel GMA X3100 graphics processor that automatically apportions system memory to create the images shown on the display. With higher RAM levels, the system allocates more system memory -- up to 384MB -- to graphics. The good news is that, with the same amount of RAM and software running, the graphics chip consistently uses the same amount of memory, so the comparisons are accurate.

To measure battery life, I fully charged the system's 5,800-milli-amp hour battery and, using my lab's Wi-Fi network, I set Internet Explorer to a Web radio station, which provides a constant and repeatable battery drain. With Battery Monitor software running, I unplugged the system and let it run down with the screen and audio adjusted to three-fourths of full brightness and volume. After the system ran out of power, I restarted it and checked Battery Monitor's Log file to find the start and end time of each run. I rounded each result off to the closest five-minute interval.

To measure the notebook's battery life and speed at the different configurations, I used several programs, each of which is downloadable:

• Futuremark's PCMark 05 exercised the system with simulated activities either individually or several at once. It showed not only an overall performance score, but results for memory and hard drive.

• CPUID's CPU-Z confirmed each configuration prior to testing.

• Simpli Software's HD Tach delivered average and burst throughput scores for a hard drive as well as access time.

• Finally, PassMark's BatteryMon gauged power use and helped with battery testing.

Test result numbers are particular to the specific testing software. However, higher scores translate into better performance.

Brian Nadel is a freelance writer based near New York and is the former editor in chief of Mobile Computing & Communications magazine. A 25-year veteran of technology journalism, his work has appeared in Popular Science, PC Magazine and Fortune.