For an average laptop user, a laptop RAM of 1 GB would suffice, to run almost all applications, including the 3D graphics and multimedia applications. But there is a common notion that the higher the RAM, the faster the laptop would be.
Though it is in a way true, the RAM is much faster than the main storage memory, yet much slower than the processor. If at tall it has to catch up with the speed of the processor, a cache is needed. Hence, more RAM does not necessarily mean faster and more efficient laptop.
In fact, the memory of the laptop would depend upon the requirement of the user and running applications on the laptop. Hence, we see that a gaming laptop would need an entirely different requirement of memory, as compared to office work or multimedia.
The laptop RAM modules are designed to fit in smaller chassis and consume less energy and so, they are quite expensive. While running newer operating systems like Windows vista, a memory of 1 GB would to be enough. This would call for an up gradation in the memory of the laptop.
Adding additional memory on a laptop generally slows down the laptop for quite sometime and it may even hang on for a while. However, a higher capacity RAM would help to ease the situation since the graphic accelerator may be slow. But it should be understood that the memory of the laptop can be speeded up only up to a certain extent.