After update android system has gone mad!

If you see gsiff_daemon at the top of the CPU list - definitely shut down and then boot back up. That process shouldn't be the top cpu usage unless it's spinning out of control.
checked today and it is no longer a problem of being at the top
 
Could this be the gsiff_daemon issue? If you go into settings -> developer options and select "show CPU processes", do you see gsiff_daemon at the top of the list?
I've had this happen 3 times in the last 6 weeks. For some people a reboot works - I've been completely shutting down and then booting back up.
The main symptom is very quick battery discharge, and Android System showing as the main use of battery.
I had a similar thing happening with my phone since the update. Initially thought it was that I changed the brightness setting way high when taking camera shots outside, but that didn't address the issue. Then I read your post, and sure as shootin' a restart took care of the issue for me and battery life is back to normal. Many thanks!
 
This happened to me last night - the gsiff daemon was spinning. After a reboot it was fine.

I don't want to rename/remove the process since I'm not sure exactly what it does. It seems to have something to do with gps / gyroscope.
 
Anecdotally - in a thread elsewhere a few people mentioned renaming the gsiff_daemon file (just adding .bak didn't stop it, but renaming it entirely did) and haven't seen any issues.
But I'm not ready to do that yet myself since I don't really know what the file does. I just keep an eye on the phone and if it starts draining very quickly I check the CPU usage.
 
I noticed this happened 3 or 4 times since the recent update a few weeks ago and the Android System was consuming huge amounts of battery (70+%). This happened a couple days ago and my battery dropped 18% in 45 min. Normally it would only drop about 5%.

I did not know about the gsiff_daemon issue but I'll check next time.

I've rebooted a couple times when this happens but still happening. Hopefully they fix it with the latest update (which I have not received yet.)
 
I just rebooted mine and hopefully that gets the phone back to normal. My battery life has been horrible since the update.