SAPPHIRE RADEON HD 4870 X2 REVIEW AT ULTIMATE HARDWARE - "Sapphire Radeon HD 4870 X2 review which also features the Sapphire Radeon HD 4850 X2. The Sapphire Radeon HD 4870 X2 has 17% higher clock speed and 45% higher memory speed than the Sapphire Radeon HD 4850 X2. The Sapphire Radeon HD 4870 X2 uses advanced GDDR5 memory while the Sapphire Radeon HD 4850 X2 uses GDDR3."

ASUS GEFORCE GTS 250 REVIEW AT ULTIMATE HARDWARE - "The Asus GeForce GTS 250 review also featuring the Pov GeForce GTX 260. The Asus GeForce GTS 250 has a 25% faster clock speed, 1% higher memory speed but the Asus GeForce GTS 250 has 64 less Pixel Shaders."

XFX RADEON HD 4770 REVIEW AT ULTIMATE HARDWARE - "XFX Radeon HD 4770 review also featuring the Gainward Radeon HD 4850. The XFX Radeon HD 4770 has a 17% higher clock speed, 38% higher memory speed but 20% less Pixel Shaders compared to the Gainward Radeon HD 4850. The XFX Radeon HD 4770 does have a disadvantage which is the 128Bit Memory Interface which is half that of the Gainward Radeon HD 4850. How will this effect the performance?"

BFG GEFORCE GTX 275 OC REVIEW AT ULTIMATE HARDWARE - "BFG GeForce GTX 275 OC review also featuring the Gainward GeForce GTX 275. The BFG GeForce GTX 275 OC is a Factory Overclocked version of GeForce GTX 275 which means that it has a 3% faster clock speed and 2% higher memory speed."