A tale of two GF FX's

1000 MHz "effective." Which is an unfortunate way to phrase it. The mere fact that it is DDR implies Double Data Rate, which means if you say it's 500MHz DDR, it should be clear that the data rate is 1 GHz. The problem comes with people mix and match and quote one in one setting and one in the other.

It's really too bad that PR pushed the "effective" frequency and so many websites went along with it. Now it just makes things unnecessarily confusing.

This is the fastest graphics memories: http://www.samsungelectronics.com/semiconductors/Graphics_Memory/Graphics Memory.htm

While they make memories that are denser and would allow for higher memory size, they only make them at relatively low speeds. I didn't even see a 350 (700) MHz part anywhere on the samsung site. The only denser DDR2 parts seemed to be ~267MHz (533MHz).