When Linux kernels were strictly 2.4.x; drivers were in /dev. The ascii codes were strictly teleptype. Xvesa vga 791 and 792 were i386 platform. You can use i386, 486, 586 cpus and better.

In Linux kerenl 2.6.x, drivers are udev in /usr; the video drivers were changed to Xorg. The ascii codes wre i686 instructions. Since the console is the operating system, the entire operating system is restricted to i686 ascii codes. The platform change, forced people to use Pentium I and better. When you use Pentium 4 or better, you have ambiguous video chipset with Analog Devices DSP cpu. So, the ATi, Nvidia and Intel video chipset all require i686 platform.

Now, we know how platform and i386 was changed to i686 performance. Much faster video and computations.