Performance describes the manner in which something functions. Those attributes that are particular to its operation, how it 'performs'.
Specifications describe what something is. Its physical attributes, its form.
https://en.wikipedia.org/wiki/Specification_(technical_standard)
"A specification (often abbreviated as spec) is an explicit set of requirements to be satisfied by a material, design, product, or service."
A spec is a set of requirements for achieving performance. It could be the amount of helium in the air required to do an experiment, consuming that helium like miners consume power.
You ask your friends to categorise "power requirements" as performance or specification. However "requirements" are something that might form part of an objects design, so naturally it would seem fit that requirements are considered part of a device's specification. Requirements exist independently of an object ever operating.
When phrasing their response, you play a clever trick and switch the term "power requirements" for "power consumption", you say your friends tell you "power consumption" is not an aspect of performance.
Power consumption is something that happens when a device is functioning. Consumption happens (more than likely in line with the specified power requirements) when the device 'performing'. It is an aspect of 'performance', which will likely be in line with the specified "power requirements".
You try to redefine this aspect of performance as being something else. However in creating this other "not-performance" category, you actually use the word performance to describe it!
If you'll notice my link to wikipedia earlier in a previous post, it should clear this up for you, assuming you understand hardware.
"performance per watt" IS performance. Saying "GH/s isn't performance, it's performance per watt" is nonsensical.
It is like saying "Mallards aren't birds, they are ducks" or "Ferrari's aren't vehicles, they are cars".
GH/s stands for GH/s...not GH/w/s. I'll concede that standard performance measurements in the mining community haven't been uniquely defined. But that only supports the fact that we need to use the terms that the people who build hardware use, which is what i'm doing and you're not.