they are both single core arm cpu’s so…
here are geekbench scores:
SGS: ~250 units
http://browser.primatelabs.com/geekbench3/search?utf8=%E2%9C%93&q=galaxy+s+i9000
RPI:~290 units
http://browser.primatelabs.com/geekbench2/2218164
the rpi is actually faster