It actually seems that iPad is running the same single Cortex-A8 core, although clocked into 1 GHz and probably fabricated using 45 nm process. This is just speculation, but for example the Sunspider test is 1/1 comparable to 3GS (10475/17360=0.603).

So overclocked N900 is pretty much on par with iPad, although the comparsion is pretty dumb as it's a completely different kind of vechile.

Second thing - the Snapdragon. According to a Swedish Android site (http://www.swedroid.se/test-av-acer-liquid-s100) A8 @ 550MHz is faster than Snapdragon @768 MHz. For example BenchmarkPi gives 5500 ms for OMAP3430, and 8300 ms for QSD8250.

It might be a software issue, maybe also related to memory bus or speeds, but in general it seems that for MHz per MHz Cortex-A8 is indeed faster than Snapdragon. Even though the cores share a somewhat similar architecture.

And that makes an overclocked N900 pretty much the fastest smartphone on Earth.