Is fog computing more efficient than cloud computing?

Advantages of fog: there is only one, reusing hardware that would be otherwise idle.

Disadvantages:

in cloud, you can put your datacenter on the location with the cheapest possible power. On fog you can't.
on fog there is some waste due to network communication.
you will likely optimize code less well because you might be targeting a wide array of different types of hardware, so more power (and time) wastage. Furthermore, some of the hardware used will not not be optimal for the task, e.g. CPU instead of GPU.

All of this makes Ciro Santilli doubtful if it wouldn't be more efficient for volunteers simply to donate money rather than inefficient power usage.

Bibliography:

greenfoldingathome.com/2018/05/28/is-foldinghome-a-waste-of-electricity/: useless article, does not compare to centralize, asks if folding the proteins is worth the power usage...

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