AMD is preparing a new GPU architecture, codenamed Volcanic Islands 2.0, that reportedly will be competitive with the new energy efficiency chips from arch-rival Nvidia. If the rumors hold true, there will be three cards, codenamed Tonga, Maui and Iceland, that will fill out the mid-range of AMD's line that has been lacking.
AMD came out with a new architecture, called Graphics Core Next, in October of last year, but the cards were focused on the high end. Only recently has the low-end of that line dropped below $200. So there is a gap to fill.
Rumors about the Tonga cards first appeared on the site Videocardz.com , which says that Tonga is a mainstream processor that will sport some changes to the architecture to increase power efficiency, including PowerTune Boost, a feature usually used in the high-end cards.
PowerTune Boost is a combination of BIOS and driver changes that allow AMD to overdrive the GPU under certain circumstances, and do it all in software. Nvidia has something similar, called GPU Boost. Basically it allows the GPU to overclock itself if the computer is running cool enough and the extra performance is needed.
Tonga would also support the technologies introduced in the R9 and R7 series introduced last year, like Mantle, TrueAudio and possible XDMA CrossFire. One sign that Tonga-basic graphics cards are aimed at the mid-range is they will only feature 2GB memory. The low-end R9 270 has 2GB, but after that the cards have 4GB, 6GB and even 8GB of GDDR5 memory.
AMD had to respond to Nvidia's new Maxwell architecture, because Maxwell was proving very power efficient. As PC World pointed out a video card based on the GeForce GTX 750 Ti (with the Maxwell core) has a TDP of just 60 watts, and a PCI Express slot can provide up to 75 watts of power, so a GeForce GTX 750 Ti doesn’t require a supplementary six-pin power cable.
AMD will either introduce the new GPU or give private briefings at the upcoming Computex show in Taiwan, the annual giant hardware trade show where all of the OEMs gather. That show is at the beginning of June, so we may get more news.