X60 CPU switches between c2 and c3 states

[xiong]

Recently, I find the cpu of my x60 operating mostly in c3 state after boot up. However if I put the system into standby and then wake it up, the cpu won't go into c3, but stay in c2, which causes much more power consumption (15watt vs 11watt). The more weird thing is, after it go into standby and wake up again, the cpu will stay in the c3 state. It is just like a toggle switch.
I am wondering what causes this problem. Unfortunately, I haven't found the tools to reveal the reason.

The cpu is core 2 dou T5500. No usb device plugged. Wlan off.

Any help and advice is greatly appreciated!

[hart22]

Does the "enable deeper sleep" CPU toggle in Power Manager do anything to this situation? I had some luck managing CPU c-states with that setting before...

[xiong]

Does the "enable deeper sleep" CPU toggle in Power Manager do anything to this situation? I had some luck managing CPU c-states with that setting before...

Thanks for the comments.

I use xp home sp3.
ThinkPad Power Management Driver 1.50
ThinkPad Power Manager 1.43

power management setting:
cpu: auto
pci: auto
etc.

I am aware that the drivers are not the latest. But the change log of the newer version does not say anything related to cpu Cx states change. I wanna figure out what prevents the cpu
entering the "deep sleep" mode.

Could you tell me where I can find the setting of "enable deep sleep"?

[hart22]

In Power Manager, under Power Plan --> System Settings there are options for Battery settings and AC settings. Set the CPU Deeper Sleep to enabled under battery. Granted this works for Power Manager 2.42 which I use; not certain if your version supports the feature.

[xiong]

In Power Manager, under Power Plan --> System Settings there are options for Battery settings and AC settings. Set the CPU Deeper Sleep to enabled under battery. Granted this works for Power Manager 2.42 which I use; not certain if your version supports the feature.

I upgraded both power manager and power management driver to the latest version
ThinkPad Power Management Driver 1.52
ThinkPad Power Manager 1.51a

besides the new user interface, nothing changed. No more settings like "enable deep sleep"
were found. Putting the computer into standby and then waking it up still toggle the cpu
operation mode like before.