Hello,

I have been researching for your question and let me tell you my humble opinion:

I have 4 Soc Boards:

Serveral Raspberry pi 2
One Orange Pi One Plus (allwinner H3 With Mali400MP2)
Odroid C2 (amlogic S905 with Mali450)
Pandaboard (Ti-omap 4430 With PowerVr Sgx540)

I have found that almos every board has a better 1cpu hashrate than the raspberry. I have tested Monero, aeon, litecoin, and magi.

for monero, The Odroid C2 has a 3.07h/s per cpu, and the orange pi has a 2.0h/s per cpu.

In litecoin, the odroid has a 1.18kh/s per cpu and the orange a 0.39kh/s per cpu.

For every scrypt the diferencies vary from one to the other.

But searching online i had the same question that you have, why isnt there any GPU support. I found that mining software relies on OpenCl for gpu mining, and almost no Embeded board has support for opencl.

for example, only From the mali 600 to the top have opencl support, mali 400 and 450 doesnt, and most SOC, dont need opencl to run 1080p. Almost all PowerVr graphics boards have opencl.

The panda has opencl support, and i was able to compile the novaspirit version of SGminer, (that by the way, found the gpu), but for some reason that i dont know, it doesnt work, once i make the file and try to use it, it wont start.

This are my findings so far.

I will try to buy an odroid xu4 that has a mali628mp, and supports opencl1.1, once i have it i will test the same code that novaspirit has.

Have a good day.

Edit1: Well it seems the reason i cant run the sgminer on the pandaboard is becouse it does not find the opencl SDK. searching over the net, it seems that Texas instrument never released the sdk for the tiomap4430, so altough the gpu has opencl support, the sdk is not available and there is no support. So pandaboard is out of the game.