A lot of my colleagues and friends who are still using Windows XP use the Windows Classic theme (i.e. the Win98-like theme, unlike the XP theme). Some of them just like it, but some others say that they do so because it is lighter and it increases performance.
Is it true? If yes, what are the performance benefits and how significant? If not, is there any reason to use classic other than if you like it visually?
Best Answer
Short answer: disabling XP themes definitely increases system performance and reduces the memory load.
Longer answer: Themes are basically a collection of graphic images that are drawn to the display buffer instead of using the older logic of using solid colors and lines. Because these themes often require resizing and/or tiling (and in newer incarnations: animation), there is a lot more work going on to display the graphic element for a button vs. the work necessary to draw the button using the older logic.
The amount of the performance increase is debatable and I would imagine it to be highly variable upon your system's CPU, memory, and a few other factors that are probably negligible (such as video drivers and video memory -- is it shared or on the video card). Although there is (in XP) no acceleration going on, there is still work that has to be done to transmit the image to the video card, and so the drivers would have some small part to play.
On systems with lesser memory resources and/or those with slower processors switching to the classic theme will definitely help out since there is no requirement to store or draw the theme graphics. On systems with more memory and faster processes, the performance increase will be less noticeable.
For current day systems, it almost always boils down to personal preference; a current machine should not show significant gains (or losses) using either mode. One from the XP era, however, will almost certainly show gains in Classic mode.