Asus GTX580 DirectCUII fan issue?

[Scania]

My GTX 580 has started behaving oddly, I run GTA V with MSI afterburner running, I have the OSD for monitoring temps, RAM / GPU usage etc.

Having finished my game and checked afterburner, I've notice my GPU fan is dropping to zero briefly and then spinning back up to ~ 60%, you can hear it doing it.

It doesn't seem to do it with any other titles but I can hear it doing the same if I close afterburner prior to launching GTA V so I don't think it's an afterburner issue.

The card otherwise performs just fine, I'm getting a solid performance with V , most settings on high / very high, it rarely dips below 50fps.

Any suggestions?

 

[Scania]

Thanks for the reply, interesting, I've had the card for a while now but never noticed it do this before and certainly not dropping to zero on the fan speed graph on afterburner.
One thing about the Asus card I have is its fans are very quiet usually, tbh I noticed it via the afterburner graph prior to listening for it, and of course, I'm now sensitive to the sound I guess...

I'll keep an eye / ear on it, I guess, perhaps, it's always done it but now I've noticed it'll just bug me!

 

[Scania]

Seems to be doing it a lot more now, fans seem to stop for periods of say 20 - 30 seconds, then they spool up to 80 -100%, temps reduce again and it repeats this cycle, only on GTA V though, tried Crysis last night cranking everything up in the game settings and Nvidia control panel, practical slide show with AA set at silly high, yet the fans were whirring away @40% quite happily.

I'm puzzled!