256mb of slow card isnt as good as 128mb of fast card, and that card is not a world beater.
It looks like a tweaked 6600 vanilla gpu and not a true 6600GT.
The old trick is at play again with "U", "Ultra" and "Turbo" appendixes to cards that are just tweaked in their class. They are manufacturers marks and have no bearing on the actual class of the card.
That card is 8 pipe, 400mhz/500mhz.
A plain 6600 gpu is 300mhz/500mhz core/memory speeds.
True 6600 GT's are 16 pipe, and good ones have a fast 500mhz+ core speed and fast 1000mhz quality ram (the amount doesnt matter so much) with tight timings.
Perhaps you should be looking for this one... or something similar....
http://www.tweaktown.com/document.php?d ... 61&dPage=2They managed to overclock it in the vicinity of 700mhz/1200mhz core/mem.
Look here.... this is a Sydney re-seller, there are both 6600 and a well priced AGP 6600 GT

Mainboard: Asus P5K-Premium, CPU=Intel E6850 @ x8x450fsb 3.6ghz, RAM: 4gb PC8500 Team Dark, Video: NV8800GT, HDD: 2x1Tb Samsung F3 RAID-0 + 1Tb F3, PSU: Antec 550 Basiq, OS: Win7x64, Display: 24&