Why does this video card specify onboard memory?

[Exce]

http://www.newegg.com/Product/Product.aspx?Item=N82E16814127272

This video card, under specifications, says it has 512MB(256MB on Board) memory. So that means its really a 256mb video card right? wheres the remaining memory. Ive never seen it displayed like that before.

The reason i ask is because im looking for a video card under 100 bucks for my sister and she was wanting this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130089

Which is almost identical in specs except it has dx10 and the other one does not.

 

[Kango]

The performance of the shared memory architecture will be much worse than the performance of the NVIDIA card. Having DX10 available with the second card will not likely come into play until DX10 games become available later this year.

The second card is far superior (IMHO) to the first card. Your sister has good instincts.

 

[mentok1982]

That is ATi's Hyper Memory thing. It is similar to Nvidia's Turbo Cache technology. If a video card
has Turbo Cache or Hyper Memory you should not buy it. Why? Because whoever made the card
was to cheap to put the memory on the card. They tried to cut costs and that is not good.

http://en.wikipedia.org/wiki/Turbo_Cache
http://en.wikipedia.org/wiki/HyperMemory

 

[Caffeinated]

The performance of the shared memory architecture will be much worse than the performance of the NVIDIA card. Having DX10 available with the second card will not likely come into play until DX10 games become available later this year.

The second card is far superior (IMHO) to the first card. Your sister has good instincts.

Agreed. Second card is better.