the Galaxy S7 will be denoted as SM-G930, and the S7 edge as SM-G935, just like the S6 is SM-G920 and the S6 edge is SM-G925, now a more granular breakdown of the model numbers has appeared. To sum it up, here are the CDMA carriers that will eventually be covered by Qualcomm's award-winning baseband modem, and the ones that will be getting the new Samsung LTE baseband that is baked into the Exynos 8890 chipset as a complete SoC solution for the firs time:While we already heard that
Verizon - SM-G930V and SM-G935V
Sprint - SM-G930P and SM-G935P
US Cellular - SM-G930R4 and SM-G935R4
China - SM-G9300 and SM-G9350 models
International unlocked - SM-G930F and SM-G935F
T-Mobile - SM-G930T and SM-G935T
AT&T - SM-G930A and SM-G935A
Canada - SM-G930W8 and SM-G935W8
Korean versions - SM-G930 S/K/L and SM-G935 S/K/L, depending on the carrier
There were rumors recently that Samsung is striving for 1:1 ratio of Snapdragon-laden to Exynos-powered Galaxy S7 handsets, but this above makes much more sense. Samsung's "Shannon" LTE modem is still a work in progress when it comes to converging the smorgasbord of carrier network standards and frequencies, while Qualcomm's Gobi solution has been polished for years to achieve the interference filtering required to cover all those standards and bands at once.
When it comes to the stray CDMA standard, Samsung might have determined it better to go with Qualcomm which has plenty of fine-tuning experience for the US carrier market, and probably holds plenty of patents here, too. In any case, both chipsets are beasts, so we wouldn't worry much about the Galaxy S7's performance, regardless of what chipset is inside.