[HTC Sensation] tsekh501:
Understanding the current generation SoC and benchmark:

SoC stands for System on a Chip. But most of us care only about the CPU and GPU on it.

Snapdragon (all 3 iterations) used the same Scorpion CPU core, at different clockspeed. The one on the Sensation has two cores, both can run up to 1.2Ghz, so if a benchmark is single threaded and very CPU heavy, the latest Snapdragon can only be 20% faster than the first generation 1Ghz Snapdragon.

Qualcomm uses a custom design for the Scorpion. Roughly speaking, the performance of the Scorpion lies somewhere between Cortex A8 and A9. In general, SoC with dual core Cortex A9's like Exynos, Tegra 2, OMAP4 will be faster in CPU heavy apps and benchmark. Yet, the Scorpion is exceptionally good at FPU heavy task, so... if FPU matter for that app/benchmark, Scorpion could pull over.

GPU wise, this depends on resolution. Higher resolution means more pixel to generate and lower benchmark score, OTHER THINGS EQUAL. The GPU on the dual-core Snapdragon is as powerful as those on Exynos and OMAP4, with one winning in some benchmark and another winning in another. Due to different resolutions on different handsets, it's hard to tell, but they are among the same class. The Tegra 2, however, has a weaker GPU than the bunch mentioned above. This may come at a surprise to everyone consider Nvidia is a graphic card company and the chip is often being promoted as "most powerful". The truth is, the Tegra 2 was supposed to be released in mid 2010 but the market wasn't ready for dual-core phones back then. So the Tegra 2 got delayed for a year, and the design of Tegra 2 was set early. But that's also why Nvidia is almost ready to launch Kal-El/Tegra 3 whatever the next thing is, because the design of Tegra 2 was done long time ago.

So if a benchmark is graphically intensive, and doesn't depending too much on CPU, Snapdragon will be faster than Tegra 2, while Exynos will be the fastest (especially since there is no qHD Exynos device out there yet). On FPU heavy CPU bench, like Linpack, Snapdragon perform exceptionally well due to its CPU design. But with benchmarks that test a wider variety of CPU function, Cortex A9 equipped SoC will beat Snapdragon. And while Tegra 2 has a weaker GPU, it may perform better in some games..... because of Nvidia's "the way it meant to be played" program. Basically it's Nvidia way to fund developers to optimize the code for Nvidia's chips, and market their games. It is no uncommon to see games that are funded by Nvidia's TWIMTBP program run faster on Nvidia's card than on AMD's card.

But what does all the above mean? IT DOESN'T F***ING MATTER AT ALL. All the current dual-core SoCs are fast enough for everything you want to do on your phone. They are equally (not) future proof, and when the future comes that your current phone is too slow, the other current gen phones will be slow too. And honestly, these ARM based SoCs are evolving so fast that none of these SoCs is really future proof. Just pick the phone that feels right or you. IGNORE those stupid benchmark numbers, and pick the phone that physically appeal to you, and pick the phone that is less buggy, or has the best monitor (for you). And if you really care about benchmark numbers, get the GSII. It has the fastest ARM-based CPU right now, one of the fastest mobile GPUs, and a relatively lower resolution screen so that it dominates all benchmarks. It also has enough plastic to be a true successor to the GS I as the most plasticky Android phone, if that matters.