"Sentient" is an ill-defined philosophical term that should be considered harmful in technical materials.
But what is clear is that AIs of today are already fairly unpredictable. Most of them aren't capable enough to make that into a major problem. Most of the unpredictable AI weirdness ends in "AI fails to do its job" rather than "AI does something dangerous".
Most. Even today, we already have notable counterexamples.
AIs get more capable over time, so if the intrinsic safety doesn't improve? Expect more of that.
There is no "proper definition" - or even one that everyone would agree upon. There is no definition of "sentience" that I could operationalize and put into a sentience-o-meter to reliably measure just how sentient a given rock, GPU or an internet user is.
I could try to put together benchmarks to estimate an AI's cyberwarfare capabilities, or instruction-following capabilities, or reward hacking inclinations. As noisy indirect estimates, of course. With philosophical mumbo-jumbo like "sentience", I don't even get that.
« no definition of "sentience" that I could operationalize and put into a sentience-o-meter to reliably measure »
That's because there's no such thing as a "sentience-o-meter", and there's no need to "operationalize" or "measure" anything. Instead, what's wrong with the definition given by Wikipedia, "ability to experience feelings and sensations"? That surely aligns with about 2500 years of philosophy and common sense, preceding all the techno mumbo-jumbo that confuses us today.
Sentience is a property of the higher forms of life, i.e. animals, which is derived from Latin "anima", meaning "soul" or "spirit".¹ Mammals and birds qualify because we relate to them easily and naturally.
Artefacts like GPUs don't even have metabolism, they can't procreate, they're dead matter, and having electricity running through them in intricate circuits doesn't change that.
[1] Some languages make grammatical distinctions based on whether an object is considered "spirited" or not, surfacing fundamentals of human perception of the world at the level of grammar.
Sentience, self-awareness, consciousness, etc.,those are terms signifying a bridge between "technical" information theory and the psychological and social realms.
Those are just as real, only far less predictable and not as easy as programming.
They're also far more important and consequential.
I don't like it when people take mumbo-jumbo that can't be pinned down, or measured, or even agreed upon, and try to insist that we should base decision-making on it. It's literally just vibes with extra steps.
The "far more important and consequential" thing you're touting is your ability to make decisions based purely on vibes. And not even consistent, broadly agreed-upon vibes like "murder is pretty bad". It's vibes of the most vile variety: "sentience is what I decided sentience is".
An average internet user is sentient, but a 1996 Nissan ECU isn't. Why? Because I said so. Tremble before my might!
You engage in baseless "comparisons" in order to frame the topic according to your wishes.
A "proper" definition represents the objective truth about the matter. You denying such a truth to exist is simply due to you preferring to act unimpeded by it.
Acting against ethical constraints doesn't become OK just because there are no laws to punish you.
Ethics tells you about real-life consequences of your actions on other people. Before any laws take effect.
In effect, you propagate moral relativism. You want to do as you please, because you said so and fancy the spoils at others' expense. People trembling before your "might".
But what is clear is that AIs of today are already fairly unpredictable. Most of them aren't capable enough to make that into a major problem. Most of the unpredictable AI weirdness ends in "AI fails to do its job" rather than "AI does something dangerous".
Most. Even today, we already have notable counterexamples.
AIs get more capable over time, so if the intrinsic safety doesn't improve? Expect more of that.