On the surface the two cards are not too different from one another. The most obvious dissimilarity is the price, the X700 Pro sells for about $199 and the 6600 GT OC goes for about $270, generally a bit more than other 6600 GTs. Now for a closer look...
BFG 6600 GT OC
BFG Technologies is a company that prides themselves on making products "for gamers, by gamers". The combination of this attitude and their quality products has earned them a pretty good reputation with the 3D crowd. As is can be tough for a company to make their 6600 GT any more appealing than a competitor's 6600 GT, this distinction has been a good thing for BFG.
The card is built around nVidia's NV43 chip, which is the little cousin of their NV40 (6800) chip. As such, it supports the 2D and 3D feature set of the GeForce 6800 series video cards. The 6600 GT features 8 pixel-pipelines, 3 vertex units, and utilizes a 128-bit memory bus. Its GPU supports Microsoft DirectX 9.0 Shader Model 3.0 and a entire host of other technologies. It can also support nVidia?s SLI multi-GPU technology.
If you are looking for some more technical specs here they are. The video card uses a 0.11u process, 146 million transistors, and has a 4200 megapixel fill rate. The memory bandwidth is rated at 16.0 GB/s.
The video card came nicely packaged, protected by a plastic box that surrounded the 6600 GT and held the rest of the contents in place. Along with the card there was a HD/TV out cable, a driver's cd, a demo's cd, a bunch of instructions, and two DVI-analog converters.
Overall this kit is not too impressive. It is nice that they include the DVI-converters, these things are not always that cheap if you are buying them at a retail store, but is it kind of necessary, as many people are still using CRTs or less expenive LCDs. Considering the added price of this card over many other 6600 GT models it would have been nice for BFG to throw you a full game- many cards at this level are including games like Far Cry.