As the title states, Samsung will be releasing the Galaxy S4 without an octa-core CPU in the UK. The news comes as a shock after Samsung had announced that the new S4 would feature an octa-core CPU but it was confirmed on Omio.
The octa-core CPU that is included in the US version is similar to how the Intel Core 2 Quad (comprised of two Intel Core 2 Duo dies on the one chip and a shared L2 cache). In this case with the Exynos 5 Octa it works with two CPUs (two quad core CPUs in this case) and the instructions are spread between the two.
As such it would be the first phone to feature an octa-core CPU in the world, but for now it is just the first in the US.