Labs

Business laptops

For each review this month, there are five star ratings: one for Performance, another for Battery Life, a third for Features & Design, then our verdict on Value for Money and a final Overall rating. We don't just pluck these figures out of the air, though: they're calculated using a complex array of benchmark results, objective scores and subjective quality ratings.

Performance

To get an impression of our machines' performance capabilities, we put each one through its paces in a rigorous series of tests using real-world applications such as Microsoft Word, Microsoft Access and Adobe Photoshop, using the same tests for both PCs and notebooks.

The overall 2D result is relative to a score of 1.00 from our reference PC - a dual-core 3.2GHz Pentium D 840 system with 1GB of PC3200 RAM, a 10,000rpm Western Digital Raptor hard disk and an Nvidia GeForce 6600 GT graphics card. In other words, if a machine scores 1.50, it's 50% faster than our reference machine overall.

Battery Life

We run three tests to evaluate a laptop's battery life. In our light-use test, we set each laptop's screen to medium brightness, turn off any wireless networking modules that may be installed, and run a simple timer application until the battery runs out; in the intensive test, we crank screen brightness up to its maximum setting, and push the processor to its limit with our demanding multitasking benchmark. This combination gives us our minimum and maximum battery life figures. In both cases, we use the power management settings most appropriate for longevity and performance respectively. Finally, we also measure the time each machine takes to recharge to 95% from completely empty, while switched on and idle.

Features & Design

The Features & Design score takes into account an array of objective measurements, such as the range of interfaces, hard disk capacity and the capabilities of the optical drive. Security features such as fingerprint readers, TPM modules and smart card slots receive extra weighting this month, given their importance in a business environment. We factor in software bundles but, more importantly, points are given for the length and type of warranty, as well as each company's performance in our Reliability & Service Awards.

The rating also includes subjective points, which are decided by a panel of judges to help overcome any bias resulting from any one person's individual taste. These points cover all those items that can't be measured objectively, such as the quality of each laptop's display, its build quality, style and the quality of speakers, and any accessories present.

Value for Money

The Value for Money score is based on a weighted average of the Performance, Battery Life and Features & Design scores; we then factor in exactly how much each machine costs (including delivery) for a bang-per-buck result.

Overall

The Overall rating is a straight average of the Performance, Battery Life, Features & Design and Value for Money scores.