We already have Google Nexus 7, Nexus 9 and Nexus 10 tablets, but Nexus 8 is still missing. It seems Google is bringing Nexus 8 soon. Nexus 8 has been spotted on Geekbench 3, but it leaves the Nexus fans in doubt.
The leaked image of Nexus 8 shows incomplete specs. Model number is specified as Nexus 8 that is running on Android 5.1.1 lollipop. It features an octa-core 1.3 GHz SoC based on ARM architecture. This could not be Snapdragon with 1.3 GHz processor.
There is a little chance that Nexus 8 would be running on Exynos Chipset. Exynos octa-core SoC is the combination of 2 Quad-core processor, and one of them runs at 1.3 GHz clock speed (ex : Exynos 5433 and Exynos 5420). However, this cannot be taken for sure.
Source (In Chinese)