[citation][nom]robisinho[/nom]The amd 7990 should get somewhere in the neighborhood of ~7000 max GFLOPs. These chips in parallel should match that in only 100w. A single (4096 core!) chip does 5.6k GFLOPs.[/citation]Assuming Adapteva can get working silicon at acceptable pricing and before their performance is completely obsolete, and assuming they can get customers to take the chance on integrating them into designs and writing the custom software that will be needed to use them, then you still have to consider the issues I cited about board vs. chip power and memory bandwidth.
I've read that the GDDR5 memory controller was one of the larger, hotter, and more challenging blocks on both AMD's and NVidia's GPUs. If Adapteva is going to support it, it will probably blow their power scaling. If not, it will certainly blow their performance scaling.
I've seen this story time and again: small company promises revolutionary architecture, then you hear nothing and eventually find out they went bust because they underestimated the technical and business challenges needed to go from an interesting concept to a successful product.
When comparing vs. GPUs, you need to distinguish between vaporware and real products that one can buy in a local electronics store. Even if this thing does become a reality, GPUs will be on at least their next architecture by then - faster, more power-efficient, and maybe even a bit easier to program.
BTW, the 3rd competitor it has are FPGAs. For tasks involving low memory bandwidth requirements, needed by customers willing to invest a lot in development, they offer even more speed and efficiency.