The Galaxy S9 and Galaxy S9+ are sure to come in dual SIM variety, just like the Galaxy S8, Galaxy Note 8, and last year's Galaxy S7. Samsung has launched dual SIM models of its flagships even in European markets this year, and unsurprisingly, the dual SIM Galaxy S9 and S9+ are being tested by certification authorities. Variants for both China and Taiwan have been listed on the FCC and Chinese Ministry of Industry and Information Technology (MIIT) websites.
Dual SIM Galaxy S9 could support “dual SIM dual VoLTE”
These listings don't tell us anything interesting, other than the model numbers for the devices, but those aren't different from the usual norm. As other websites that have covered this story suggest, the Galaxy S9 and S9+ could launch with support for offering VoLTE calls over both SIMs instead of limiting either of the SIMs to 2G or 3G network, which is the case right now. That's thanks to the X20 modem inside the Snapdragon 845, although it will also depend on Samsung being able to implement the same technology on its Exynos chip. If that fails, the company is likely to keep the “dual SIM dual VoLTE” feature of the Snapdragon chip out of the two flagships (or keep it limited to the Snapdragon version in China).
It also remains to be seen how widely available the dual SIM Galaxy S9 and S9+ will be. Thanks to the new Snapdragon 845 modem, it would be easy for Samsung to launch the dual SIM models in the US, at least for the unlocked variants. It would be great to see every unlocked model in every country carrying two SIM slots, if not support for running two SIM cards and a microSD slot at the same time. But it's likely to continue to be a hybrid slot, given how space inside premium smartphones these days is, well, at a premium. Time – and further leaks and rumors – will tell.