When Samsung announced its Galaxy S II lineup for the US earlier this month, it was confirmed that both the AT&T and Sprint versions would use Samsung’s own 1.2GHz dual-core Exynos processor. No such confirmation was made for the T-Mobile USA version. Samsung Telecommunications Marketing Manager Philip Berne has confirmed that the T-Mobile variant will not use the Exynos processor. Instead, it will use an unspecified “dual-core processor” (around the 3:00 mark in the video below)
As for what this mysterious processor could be, one obvious candidate would be an NVIDIA Tegra 2. Another option might be the 1.2GHz dual-core Qualcomm APQ8060 processor. Older rumours about the Samsung Hercules (which is almost certainly none other than the T-Mobile Galaxy S II variant) support that it would be a Qualcomm processor but shed no light on which.