GDDR3 memory and 256-bit ??

[GrefMofovich]

I'd like to know what's up with this newfangled GDDR3 ram on video cards? Also, I've heard of 64-bit memory coming on the cheaper video cards, and 128-bit being on the more expensive, but there's a 256-bit now too? How do I know I'm getting the best video card for performance?

It's so confusing that the same models have 64 bits or 128 bits and most websites don't even tell you which one they sell. Isn't there a significant difference? Hope someone can clear this up, before I lose my mind.

-GM

[bob05]

Yes, there is a significant difference from 256 and 128 bit (see Boycott Sapphire (http://www.theinquirer.net/?article=16599)). You are correct, most sites don't tell what the memory bandwidth is. If I'm not mistaken, most (if not all) GDDR3's are 256 bit.

[PacNW CE]

Think of the bit ammount as if it were lanes on a freeway. Can you move more traffic through 128 lanes or 256 lanes?

The 6600 and x700 cards from Nvidia and ATI respectively have GDDR3 memory @ 128 bits. I don't know how graphics data moves through the memory, in large blobs, short blasts, or somewhere in between. All I know is that My 9800 pro with 256 bit memory can beat the 6600 and x700 in framerate during certain memory intesive benchmarks.