We've seen the benchmarks and how ATI has comeback from nowhere to reclaim the mainstream performance crown, but what's behind this sudden change that makes the new HD 4000-series so compelling? We dive deep down inside to find out.

Nvidia's GT200 GPU arrived just a few days ago - we dive deep into the architecture to find out what's changed inside the chip. We take a look at the GeForce GTX 280's performance, while also looking at GPU computing--and CUDA in particular--to see how things are progressing in that space.