Wut?
1080p Manhattan:
TK1: 28.1 FPS
Exynos 5422: 8.6 FPS
Assuming 650MHz for that TK1 and a linear scaling with clocks, performance at 150MHz would be (150*28.1)/650 = ~6.5 FPS.
This doesn't look like running circles..
You know the world doesn't spin around 3D only especially in that market; now make the same exersize again with something compute oriented for instance and try quirking around endlessly with weird compiler optimisations to keep half of those Vec4 ALUs in Malis busy, while GK20A due to its scalar ALUs will come as close as possible to its peak FLOP values.
Besides it was just a case example; no IHV would be as idiotic to develop such a GPU as wide to clock it at just 150MHz under 28HPm. Likelier case would be a fraction of the 192SPs the GK20A right now has with an =/>700MHz frequency, which of course doesn't change a bit the above.
For the record's sake Xiaomi seems to be experimenting with different frequencies since the results are constantly bouncing up and down; look at those here
http://gfxbench.com/subtest_results_of_device.jsp?D=Xiaomi+MiPad&id=555&benchmark=gfx30
At theoretical 150MHz GK20A gives 57.6 GFLOPs FP32; how many GFLOPs has the MaliT628MP6 in the Galaxy S5 exactly?
http://community.arm.com/thread/5688 (no it isn't clocked at "just" 533MHz afaik)
Sure, Samsung's SoC division hasn't been terribly successful ever since they lost access to Intrinsity's services, but I think you're being a bit too melodramatic.
Melodramatic? How about you give me a viable persentage of how many smartphones with Exynos Samsung actually sells in total and how many with Qualcomm's SoCs. They're not using less S8xx SoCs lately but increasingly more and it sure must be because of their engineering marvels no one wants to have not even Samsung mobile.
Whatever made you believe that tesselation is a power hog by itself, is probably wrong.
If the final visual result is the same and both target the same framerate, a model with lots of geometry will probably consume more power than the same model with less geometry+tesselation.
Tesselation can - and should - be used as a power/performance saving feature in mobile devices.
There's a comment from JohnH here in the forum about it and him as an experienced hw engineer I trust more than you, for reasons I hopefully don't have to explain.
***edit: to save you from searching
http://forum.beyond3d.com/showpost.php?p=1834992&postcount=23
http://forum.beyond3d.com/showpost.php?p=1835124&postcount=26
Besides that I mentioned die area for the tessellation unit alone, which obviously flew completely over your head.
Qualcomm's (and all others') pursuit for full DX11 compliance are probably related to Microsoft's plans for Windows 9.
Good for them. For windows I'll personally take a real windows machine with a proper desktop GPU (even low end) instead. The S805 doesn't sound like a solution I'd want for such a case.