-Speed fan is giving you motherboard temp, as is easy tune... both of them are poling that temp from the motherboard socket
-coretemp, aida64, and hwmonitor are all giving you a temp of 13-15C on the cpu.
I should make a guide on piledriver temps since it seems i write this once a week. Piledriver like every cpu amd has made since the phenomII does not have an actual thermometer on it's cpu. It uses a mathematical algorithm to "estimate" it's core temps. I don't know how it does it, i just know it doesn't work well on say... 2/3 of the chips.
Each series of AMD cpus has it's own quirks with it's temp monitoring, but you can make some generalization about them...
PhII - typically would give you the right core temp + or - 5-20C... you just had to figure out what your cpu's actual temp was (it ran about 5C hotter then the socket) and you would know what temp your PhII was at all times. My old PhII reported it's temps about 5C cooler then it actually was for example.
Bulldozer - the temp monitoring never really worked on bulldozer, most chips wouldn't even give you a temp~
Piledriver - Piledriver has 4 types of chips...
1) works as it should. you see this more on the Richland apu lineup then you do in the fx lineup.
2) reports an accurate temp above a certain temp point, and an inaccurate one bellow it (for example, my fx8320 reports a solid cpu temp over 32C, but under it reports 12C or so as the core temp, it looks like yours might be similar),
3) the next type is the opposite, it reports a good temp under a certain temp, and a silly temp over it (usually something like 155C or 255C, something insane that can't possibly be right),
4) and the last one simply doesn't work at all.
Now you can verify how accurate your core temp is by checking out the socket temp on the motherboard. When piledriver reports it's temps right, the core temp should be reporting just about 10C colder then the motherboard socket temp. Because if this people have come to call the piledriver core temp the "surface temp"... it's believed it's representative of the temp on the top of the heatspreader. While the actual core temp is unknown, it's believed to be much closer to the motherboard socket temp.
Understand that richland apus tend to report a solid core temp figure you can probably trust as moderately accurate as we'd assume a core temp to mean. I don't know about kaveri yet, AMD priced those chips out of the market so no one seems to have one to report, but i've not seen anything to indicate they don't report their core temps accurately either.