According to SweClockers AMD is planning to launch more Radeon R9 290X graphics cards with 8GB GDDR5 memory on board in November.
Radeon R9 290X with 8GB will be exclusive to three partners: PowerColor, Sapphire and Club3D. Sapphire is the only manufacturer with two Radeon R9 290X 8GB cards already released. While you can still easily find Vapor-X, the R9 290X Toxic was limited only to handful of units, so technically your choice is restricted to one model only.
The new Radeon R9 290X graphics cards are expected to compete with recently released GeForce GTX 980, which as you know, offers better performance and lower power consumption. AMD is still in the lead in 4K+ market, but most gamers are still locked to 1080p resolution, so I’m not really sure what is AMD trying to accomplish here.
These new cards are said to cost around 10% more than 4GB variants. It is possible that AMD is planning Never Settle bundle update along with the launch or these new cards.
More Radeon R9 290X 8GB are to be released on November 6th.
Source: SweClockers