Well Peter and I were unsure... we couldn't find a benchmark with them head to head.. and since the HD 4830 is basically a slightly crippled HD 4850, I put it up there as a placeholder..
8800gs is on the revision die i believe so it out performs the 320. and the 1gb hinders performance somehow unless you're playing on mad high resolutions.
the GS has a 192 bit interface and the GTS 320 has a 320 bit interface....that means that memory bandwidth is much greater for a similar amount of memory (64mb isnt much of a diff tbh), and the no. of SPs are the same as well...so all in all i believe theoretically given the specs the GTS 320 should score higher...its never let me down and fair enough on the 1GB deal...