Published Kal-El (TEGRA3) performance: is NVIDIA SoC truly faster than a Core2 ?

All peoples involved in IT and computer technologies in the last decade know very well NVIDIA: this graphic & compute chips design company reached many important target and set new state-of-the-art performance in about any marked where it operated.

Some day ago, NVIDIA uncovered its next-generation SoC project, codenamed Kal-El. This SoC is going to set new performance standard in its area, featuring four ARM Cortex A9 core (each with NEON support, thanks to the integrated MPE) and a renewed, 12 core wide graphic controller. Anandtech did a great job in explaining Kal-El architecture, so I advice anyone interested in SoC performances to read his article here: http://www.anandtech.com/show/4181/nvidias-project-kalel-quadcore-a9s-coming-to-smartphonestablets-this-year

However, NVIDIA did not limit itself to announce its new hardware beast, but showed some benchmark numbers to prove the superior speed of Kal-El. The used benchmark was CoreMark 1.0 (you can read about it here: http://www.coremark.org/home.php), a synthetic ALU and FPU benchmark. Kal-El performs very well here, doubling Tegra2 performance: this is an extremely great accomplishment, as the tested Kal-El silicon was only 12 days old, and this is a testament to NVIDIA's ability to design top-notch chip.

Moreover, Kal-El was not only compared to current Tegra2 hardware, but also against an aging Core2 T7200 (a dual core mobile processor @ 2.0 GHz with 4 MB of L2 cache) and, by NVIDIA measurement, Kal-El is faster than this x86 processor:

However, many readers discovered a strange thing: the compiler version used for the Core2 processor is very old, and the optimization flags used are much more conservative than the ones used on the two NVIDIA SoCs:

As you can see, NVIDIA benchmarked its processors with a recent GCC version (4.4.x branch) and very aggressive optimization settings (they used not only O3 but tuned some hardware-specific settings also). On the other hand, the Intel processor was benchmarked with a very old GCC version (3.4.x branch) and only “normal” (O2) optimization settings.

These consideration raises an important question: is Kal-El truly faster than a Core2 processor, or this result is only an artifact of the different compilers and optimization settings? Well, in this article we will try to answer to this question...