Easy to misread and assume Bytes, certainly. And lazy for not doing the 1/8.
But is there any value to coverting to bytes (B) from bits (b) in this particular case? The total memory (256MB or whatever) that the card has isn't all for the frame buffer, it's for textures and other stages of the rendering pipeline.
But ok. Based on the max res of the card given earlier, that would be 12MB for the fb. The LCD needs 5MB at 32bit, 3.75 @ 24. The widescreen 8.79 & 6.59.
In either unit, at 32 bit color Tony's speculation is reasonable.