Here are some tests I've done on my devices compiling Povray 3.6 (single threaded) and rendering the benchmark scene. I was rather surprised that my new Nexus 4 (Qualcomm S4) is slower per core than my SGS II (Samsung Exynos 4). Yet the Nexus 4 doesn't feel any slower and is my main phone now due to the larger and higher resolution screen.
Athlon II x4 (2.8 GHz): 179.82 pps ; 64.22 pps/GHz
Exynos 5 (1.7 GHz): 77.36 pps ; 45.51 pps/GHz (-mfloat-abi=hard -mcpu=cortex-a9 -mthumb -mthumb-interwork)
PowerPC 750 (700 MHz): 20.47 pps ; 29.25 pps/GHz
Exynos 4210 (1.2 GHz): 29.90 pps ; 24.91 pps/GHz (-mfloat-abi=hard)
Pentium 4m (1.5 GHz): 36.24 pps ; 24.16 pps/GHz
S4 Pro APQ8064 (1.5 GHz): 31.81 pps ; 21.20 pps/GHz (-mfoat-abi=hard -mcpu=cortex-a15)
Atom N270 (1.6 GHz): 28.96 pps ; 18.10 pps/GHz
Unfortunately can't post all the data I have because this site thinks there're too many 'junk' characters already...