AMD is reportedly already preparing its next series of Radeon HD 7000-series GPUs, and planning to start mass production of the new chips in May this year.Taiwanese tech site DigiTimes claims the move will follow the introduction of the company's Radeon HD 6670, 6570 and 6450 GPUs this month, citing graphics card makers as its source.There's no word on the specifications of the new GPUs yet, but previous rumours have stated that they will be fabricated using TSMC's 28nm facilities.We originally expected to see new GPUs based on TSMC’s 28nm manufacturing process in autumn this year, and the smaller transistors will represent a large step down the process scale from the current 40nm process used for AMD’s Radeon HD 6000-series and Nvidia’s latest GeForce 500-series GPUs.The usual benefits of a process shrink are higher frequencies and more space for resources in the die. This can all be squeezed into a piece of silicon that’s the same size as the previous comparative GPU, so costs per comparable GPU (or card) usually remain similar. Previous rumours have suggested that the new range of GPU, codenamed Southern Islands, will be based on the same architecture found in AMD's current Cayman-architecture chips, such as the Radeon HD 6900-series. This seems sensible, given AMD's claims that the VLIW4 stream processor architecture of Cayman is more efficient per mmof silicon than the VLIW5 design of its previous GPUs.However, while we’d expect some upgrades in other areas of the GPU design to complement the stream processor design, it looks as though we shouldn't expect anything as radical as the original Nvidia Fermi design, which broke up the front-end of the GPU and distributed various elements throughout the design.There may still be room for adding new stream processors to the GPU, though, especially if AMD does indeed deploy a 28nm process. There are no figures yet, of course, but given the huge process-shrink, a doubling of the stream processor count seems a conservative estimate. This could potentially result in the fastest GPUs featuring over 3,000 stream processors.Are you excited by the rumours about the Radeon HD 7000-series, or are you going to wait until you see the reviews here before making a judgement? Let us know in the forums