Good point about "communicating the entire time that its death was imminent". Regarding the power tests I think the relevance is that the drives lie to the OS

Good point about "communicating the entire time that its death was imminent". Regarding the power tests I think the relevance is that the drives lie to the OS about sync, and just claim they completed it when its in their cache, and then hope they can write it to flash before power loss / before the capacitor runs out. The cache wouldn't be a problem if it could be reliably flushed. As it is they will corrupt the integrity of anything that relies on syncs / write barriers like databases.