🚀 go-pugleaf

To be clear, the number of bits that a card advertises is the internal
maximum wordlength that the video card's graphics processor can handle.  For
example, a 64 bit card can process an instruction word that is 64 bits long,
or 8 bytes, at a time.

The number of bitplanes that the card supports is a measure of how many colors
it can display.  A 24 bit color display, regardless or resolution, is able
to show 16.7MM colors at once, also called Truecolor.  32 bitplane display 
shows the 24 bit color, plus 8 alpha channels.

The two concepts are only indirectly related.  There have been 24 bit cards
on the market for ages (until recently they have also been absurdly expensive),
and I would doubt that the earliest Targa boards were more than 32 bit 
processors.

Similarly, if you got a 2MB 128bit card, you would still only get 16, rather 
than 24, bit color at 1024x768, regardless of the 128 bit processor on the
card.

If you care about the number of colors, the onboard memory is the number you
need to focus on.

Regards,