You can always check out the Anandtech reviews, there are many head to head benchmarks between the two chipsets, although they were all tested more than a year ago. Anyway, i815 tend to lead 694x in gaming under Win9x, but things get tightened up in Win2k for some reason. I think the 694x has better memory performance, but overall a bit than i815 in real world tests. The disadvantage of i815 is obviously the memory limitation, only 512MB, compare to 694x's 1.5GB; and the other advantage would be price, i815 generally cost more. I personally will take i815 over 694x, because the boards based on i815 are better designed, a lot of them are equipped with 1MHz increments, so they're good for overclocking. But don't discount the 694x, it's a very comparable chipset.