Graphics cards for laptop computers vary greatly from desktop versions, and will require a different video driver than desktop versions.
A driver is a piece of software that tells your computer how to access and use a particular piece of hardware. In the case of a display adapter or graphics card, the video driver tells the computer how much memory the card commands, how fast it is, and how quickly it can send images to the monitor.
Graphics cards designed for laptops must be much smaller and plug in to a different type of motherboard architecture than their desktop cousins. For this reason, it is entirely impossible to install a graphics card designed for a desktop computer into a laptop, and it is impossible to install a graphics card designed for a laptop computer into a desktop. These two pieces of hardware are entirely different in form and function.
Like their desktop cousins, laptop graphics cards contain the same crucial elements: The input/output chip or BIOS chip, Digital-to-Analog Converter or RAMDAC, Output Port, Motherboard Connection, and the Graphics Processing Unit or GPU.
Historically, Laptop computers have been less powerful than desktops in regards to pure performance. The miniaturization of laptop components often requires a reduction in memory or processor size, which reduces overall horsepower. Further, laptops are much smaller and have more constricted ventilation, which increases heat generation, effectively reducing the maximum speed at which laptop components can operate without failing.
Additionally, laptop computers are generally more expensive than desktops, and are therefore more often used as strictly business machines rather than multimedia or gaming platforms. However, over the last few years, reductions in component cost have introduced new options for those who seek a strong gaming platform with the utility and portability of a laptop frame.
The two largest manufacturers of high-end graphics cards for laptops are Advanced Micro Devices (AMD) - previously ATI Technologies - and Nvidia Corporation. Each company boasts a newly expanded list of graphical components for laptops, and benchmark scores on machines built around these new graphics card rival those of desktops.
As of this writing, the Nvidia GTX 400 series is Nvidia's latest line of laptop video cards, and they currently occupy the top spot in overall performance for laptop systems. With a 3DMark 06 benchmark score of over 15,000, Nvidia stands head and shoulders over the highest scores from rival ATI.
More importantly, the GTX 400 line supports DirectX 11, Microsoft's newest version of multimedia-enhancing software for Windows.
But there are drawbacks - most notably, power consumption and heat. Laptops that run Nvidia 400 cards are powerful, no doubt, but they will drain battery life at a nearly 85% increased rate over standard Windows applications. This means a 6 hour battery will last less just over 3 hours if the graphics card is running at capacity. Also, the massive heat generated by the GTX 400 can cause stability issues if used for extended periods of time.
Clocking in with a 3D Mark 06 benchmark score of nearly 13,000, the Radeon 5800 series is no slouch. Like Nvidia, the 5800 series takes advantage of the newest version of MicroSoft DirectX11.
While power consumption for the Radeon 5800 series is comparable to the Nvidia 400 line, AMD/ATI does have one advantage - heat. The heat generated by the Radeon 5800 products is nowhere near the level of the Nvidia 400 line, meaning laptops built around AMD/ATI graphics cards are more stable and able to run longer periods without interruption.
It is the opinion of this writer that the Nvidia series of laptop graphic cards generally tend to be more detail intensive, while an ATI laptop graphic card tends to be faster and more stable as a general rule. For users seeking cutting edge post-processing, Nvidia is generally the way to go. If raw power or extended use is preferable, ATI is typically the right choice.