The Galaxy S6 may be just a month old, but Samsung is already testing the processor that will power its successor, a new report claims. The South Korean company is said to be working on a new chipset that will feature custom-designed cores codenamed Mongoose.

The chips are said to be based on ARMv8 architecture, and sources say Samsung has been working on them since 2011.

A previous report from PhoneArena claimed the chip’s maximum clock speed is 2.3GHz per core, while early benchmarks promised 45% better single-core performance than the Exynos 7420 chip in the Galaxy S6 and S6 edge.

Now PhoneArena points to new development tools for ARM cores, which include support for a so-called Samsung Exynos M1 core.

“This confirms that Samsung is hard at work at new CPU cores for its smart products, and goes to suggest that the giant’s software development partners are already toying with it as well,” the report reads.

If the information is accurate, it also confirms that Samsung is likely sticking with its own Exynos chips going forward, rather than reverting back to Qualcomm’s Snapdragon family for future devices. But that’s hardly surprising given how well-received the Exynos 7420 has been since its debut.

Mass production of Samsung’s new Exynos chip is expected to begin in 9 to 12 months, which means it won’t be ready in time for the Galaxy Note 5, and will likely appear in Samsung’s next-generation Galaxy S family.