Yes. If and only if you have a battery-backed cache. I know of no IDE drives that have that, but there's nothing about the spec which makes it impossible.
Relevant section: <quote> Maybe that is why there is a vender disk-cache dump zone on the edge of the platters...just maybe you need to buy your drives from somebody that does this and has a predictive sector stretcher as the energy from the inertia by the DC three-phase motor executes the dump.
Ever wondered why modern drives have open collectors on the databuss? Maybe to disconnect the power draw so that the motor now generator provides the needed power to complete the data dump... </quote>
SEEMS to imply that some IDE drives at least have enough power left after power's off to store the write-cached data to disk.
The rest of the email's not very reassuring, though, but note that this email's two years old.
Anyone want to test? :)
Linux homer 2.4.18-14 #1 Wed Sep 4 13:35:50 EDT 2002 i686 i686 i386 GNU/Linux
4:30pm up 280 days, 8:00, 8 users, load average: 6.05, 6.01, 6.02
Description: PGP signature