There are two new graphics cards up for sale, or there will soon be, straight from Club3D's labs. They are based on AMD's Radeon HD 7750 adapter and have 4 GB of DDR3 VRAM and 1 GB DDR3, respectively.
Club3D is doing what PowerColor did the other day, namely release the Radeon HD 7750 graphics adapter in single-slot form and with more memory than it needs.
The Radeon HD 7750 4096 MB DDR3 is a fairly self-explanatory name really, stating what card it is and how much RAM is present: 4 GB. It is detailed here.
There is a second board up, identical to this one in looks and capabilities, but with only 1 GB of DDR3: Radeon HD 7750 1024MB DDR3. It can be found here.
The adapters are aimed at customers who want a good motherboard but can't afford the GDDR5 versions.