From Fudzilla:

Nvidia Geforce GT 520 launched in April as a low-end Geforce 500 series graphics card. Today, we’ll introduce you to Gainward’s GT 520 1GB SilentFX.

From HardOCP:

Would you be better served by a feature rich HD 6870 or a plain-Jane HD 6950? The GIGABYTE HD 6870 Super Overclock certainly has features of plenty with an improved three fan cooling solution, factory boosted frequencies and high quality components. Enough to trump a reference Radeon HD 6950 for the money?

From X-bit:

AMD: It Is Impossible to Unlock Additional Stream Processors on Radeon HD 6790

Not all graphics cards are equally good for experienced end-users, who are not afraid of pushing their performance to the maximum possible level. Advanced Micro Devices officially confirmed that its latest AMD Radeon HD 6790 cannot be transformed into more powerful solution by re-enabling disabled units.

From Xbit:

Although Nvidia has made some serious progress recently, AMD’s graphics department is still in the lead when it comes to dual-processor graphics cards. Announced as far back as November 18, 2009, the Radeon HD 5970 remains the fastest single-PCB graphics solution available. You can only build a faster graphics subsystem by using multiple graphics cards whereas the Radeon HD 5970 needs just a single PCI Express x16 slot and a high-wattage power supply.