Shaders, which is a term for software instructions that calculate graphical rendering effects have a great deal of influence over how good or bad a game can look. Programmable shaders, in lay man’s terms, allow a developer more freedom with regard to how their game calculates light and shadow data, thus increasing the kinds of effects they can achieve. The 3DS doesn’t utilize these.
Instead, it uses a range of commonly-used fixed shaders, which, judging by the 3DS games we’ve seen so far, appear to be doing a good enough job of making games look visually impressive. A recent Iwata Asks interview with some of the system’s hardware designers reveals that this decision was made to conserve battery life. This ties in with the power consumed by the 3DS screens’ backlight.
LCD screens, such as the ones on the Nintendo 3DS, use an internal light source known as a “backlight,” which illuminates them. Stereoscopic 3D visuals deliver a separate image to the right and left eyes, thus halving the the amount of light delivered to each eye. 3D visuals require that this backlight be increased in brighten to deliver a 3D image that appears as bright as a non-3D one.
Due to this, the 3DS includes a power saver feature, according to Ryuji Umezu (pictured above) of Nintendo’s Research and Engineering department. This feature controls the brightness of the backlight depending upon the brightness of the in-game screen being displayed. When the in-game scene is darker, the backlight, too, dims, allowing for power to be conserved.
Umezu says that setting the backlight to the brightest level and turning the power saver function off will give you about three hours of battery life. However, if you turn the power saver function on, battery life increases by about 10-20%. Setting the backlight to the darkest setting will give you around five hours, although, the power saver mode makes less of a difference in this case.
The system’s 3D visuals have an effect on battery life, too. With the backlight set to the brightest setting, toggling 3D on or off can make a difference of 25% to battery life. Streetpass functionality and Wi-Fi have an effect on battery life as well. Nintendo previously revealed that the system could take up to 3.5 hours to complete a full charge.