The reasons manufacturers slap on 256MB of memory (and eventually 512MB) is because it's a numbers game. The average consumer knows NOTHING AT ALL about computer components. Actually, that statement would probably be grossly exagerrating their knowledge - it's some negative value (we've ALL seen it).
Anyways, Joe Schmoe computer buyer sees 512MB and he will think that more memory = more performance. You might mention the difference between 16 and 12 pipelines, but those numbers pale in comparison to the large values of 2^x and to Joe Schmoe that extra 256MB of memory will make all the difference in the world. What he doesn't realize is that MS Word and online poker won't be much faster - if at all - with the latest and greatest video card with an obscene amount of money. But in his head it's faster and ultimately he wins because he thinks he got something that will really increase his computing experience and the manufacturer wins because they pawned off some powerful card onto Joe Schmoe who has little need for anything above integrated graphics.
Anyways, Joe Schmoe computer buyer sees 512MB and he will think that more memory = more performance. You might mention the difference between 16 and 12 pipelines, but those numbers pale in comparison to the large values of 2^x and to Joe Schmoe that extra 256MB of memory will make all the difference in the world. What he doesn't realize is that MS Word and online poker won't be much faster - if at all - with the latest and greatest video card with an obscene amount of money. But in his head it's faster and ultimately he wins because he thinks he got something that will really increase his computing experience and the manufacturer wins because they pawned off some powerful card onto Joe Schmoe who has little need for anything above integrated graphics.