Octocore cpu i7 3.0ghz 5960x

[Dirk Broer]

Well, I hope for the 32-core/64-thread model to have a TDP of at max 140 Watt, which would mean for a -as yet hypothetically- quad mobo 4x140=560 Watt (TDP)
And I hope you can start with just one CPU on that board, later adding more as budget permits. A dual setup is only 280 Watt (TDP) and still 128 threads.
BTW: 8-channel RAM means each CPU/Mobo ought to have at least 8 RAM DIMMS...Socket 1366 Nehalem had six RAM slots for triple channel RAM, Socket 2011 eight RAM slots for quad channel, remember? So expect sixteen RAM slots per Zen-Opteron, that's 64(!) RAM slots to fill for a quad Zen-Mobo.....
560 Watt (TDP) for 256 threads is slightly more than 2 Watts (TDP) per thread. I think a quad Zen is cheaper to run than a 'classic' farm:
560 Watt can easily be reached with some 125 Watt FX CPUs, 95 Watt FX CPUs, 100 Watt APUs or 65 Watt APUs.

In my case, x86-64 farm:
i7-3770: 77 Watt
A10-5700: 65 Watt
A8-3870K: 100 Watt
A8-3820: 65 Watt
C2Q8200: 95 Watt
Athlon 5350: 25 Watt
Athlon 5350: 25 Watt
Athlon 5350: 25 Watt
A8-3850: 100 Watt (decommissioned in favour of a 25 Watt 5350, now part of Emergency only reserve)
A6-3500: 65 Watt (decommissioned in favour of a A10-5700, long-time part of Emergency only reserve)

ARM farm
Raspberry Pi 3 Cortex-A53: 5 Watt (inactive yet, just bought)
Raspberry Pi 2 Cortex-A7: 4 Watt
Raspberry Pi 2 Cortex-A7: 4 Watt
Raspberry Pi B+ ARM11: 3 Watt
BeagleBone Black Cortex-A8: 3 Watt
Cubieboard 4 Allwinner A80: inactive, because I can't get video from it -seems to be working right further, all lights function. Even get different shades of black-grey on screen while booting.
Banana Pro Allwinner A20: inactive, because I can't get video from it -not sure whether it even boots, only one red light blinking. May have defective SD-card reader...