It looks like AMD's add-in board (AIB) partners are preparing new Radeon R9 390 video cards with 4GB of VRAM, compared to the 8GB of framebuffer on the current R9 390 models.
The new Radeon R9 390 4GB models will feature the Grenada Pro GPU, which is a revised version of the Hawaii Pro GPU on the 28nm process. This means we'll see 2560 stream processors, 160 TMUs, 64 ROPs, and a GPU clock speed of 1GHz. The 4GB of GDDR5 will be clocked at 1.5GHz (6GHz) with a 384-bit memory bus. The original R9 390 8GB models were aimed at 4K gaming, but the new 4GB models should hit the 1080p/2K gaming market, with more than enough horsepower to drive 60FPS at both resolutions.
The Radeon R9 390 8GB models still sell for around $329, while the new 4GB models will fall into the $299 price, or lower. This means that the R9 390 will be priced right against NVIDIA's GeForce GTX 970. As for the models, SAPPHIRE is preparing its Radeon R9 390 4GB Dual-X OC card, XFX has its Radeon R9 390 4GB Black Edition OC, PowerColor with its R9 390 4GB OC Edition and more. On average, the new R9 390 4GB model is around 10% faster than the Radeon R9 290, so if you're upgrading your old R9 290, now could be the time.