Display/graphics drivers does not boost your system, it provides only good clarity to ur screen with less flickering during the PC usage and only optimize ur display effects.
As u have mentioned ur graphics driver is old, it may be incompatible with some games or HD videos, this causes ur pc to run with more CPU usage i believe. Old or new it donesnt matter unless the game graphics itself adjusts to the Video Card settings. I believe in some cases like this overclocking might help you run ur applications smoothly, but the performance might dropdown if u are using a laptop.
If u are updating ur graphics card always update it through the vendors site itself.