laggy 15fps on Octacore 2.3 ghz cpu Tab S

[fivefeet8]

The device has a marketing gimmick of 8 cores, but only 4 are used at a time. Either the fast cores at 1.9 ghertz, or the slower power saving cores at 1.3 ghertz. It's not a true 8 Core CPU since you can't use all 8 at the same time. And it's also running the Exynos CPU, not the Snapdragon chips, so it has the Mali T628 GPU. But I don't believe you have the Exynos if the CPU is running at 2.3 ghertz. You may have the LTE version which has a Snapdragon 8xx chipset with an Adreno 330.

Most games should run ok with framebuffer disabled. Things have improved a lot from before, but Adreno devices still cannot run most games with it enabled.