Dual 256-bit memory interface

[ACESHIGH]

Just browsing & saw this card ...
GV-RX80L512DE

Powered by ATI Radeon X800 XL VPU
Supports PCI Express and 16 pipelines
Microsoft DirectX 9.0C and OpenGL 2.0 support
Integrated with 512MB GDDR2 memory and dual 256-bit memory interface
Features DVI-I / D-sub / TV-OUT
Supports HDTV function and HDTV cable enclosed

http://www.giga-byte.com.tw/Products/VGA/Products_Overview.aspx?ProductID=1294

compared to ...

GV-RX80L512V

Powered by NVIDIA GeForce X800 XL VPU
Supports PCI Express and 16 pipelines
Microsoft DirectX 9.0C and OpenGL 2.0 support
Integrated with the industry's best 512MB GDDR3 memory and 256-bit memory interface
Features dual DVI-I / D-sub (by adapter) / TV-OUT
Supports HDTV function

http://www.giga-byte.com.tw/Products/VGA/Products_Overview.aspx?ProductID=1257


Does the dual 256-bit memory interface make the card run faster / utilize the 512MB ram more efficiently? Ideas?

 

[ACESHIGH]

I think the Nvidia referance is a typo, rest states ATI & pic is ATI logo.

Not buying one or anything like that, just curious as i havent seen dual 256 bit interface before (cant say i really looked for it).

More curious, if the cards were identical if anyone knew how much performance boost a dual v single 256 bit interface would give.
If it can be done on a one card, why wouldnt you do it on new top of the range cards?