Slow Chassis fan speed

[PhilGP]

My new PC has been suspended most of the day. When I got home I hit the space bar to wake it up.
I instantly saw a warning about low fan speed from the Asus System Information control panel.

The speed was 487rpm. Over the next 10mins, the fan picked up to well over 600 rpm and changed from RED (warning) to white when it exceeded 600rpm.

Could it just be the suspend/hybernation that dropped the speed?
Is it a concern as it is now recovered?

MB: Asus M5A87
CPU: Phenom II X4 965e

figures when I first noted this ...
CPU Temp: 31.0 'C
BM Temp: 21.0 'C

CPU Fan: 1936 rpm (PC is idle)

I ran a stress test and the figures jumped to ...
CPU: 48.5 'C
BM: 21.0 'C
CPU Fan: 2866 rpm
Case Fan: 633 rpm .. not a huge jump

 

[Corfate]

I usually leave my PC is sleep mode when im at school. When i get back and hit space, if i have speedfan running, it'll show my cpu running about 25 degrees, and my fans hardly running at all. This is because the pc isn't doing anything at all really, so the CPU is not overheating. This allows the fans to be almost shut off completely. As soon as i awake the pc, the fans boot back up, and the cpu temp rises.

It's nothing to worry about

 

[PhilGP]

Thanks ... it has been suspended a few times and I havent noticed this before.
The room it's in is cold today so that will contribute a bit.