Dual Core Speed of X61 Decreases When Battery is Removed

[anselnew]

Surprising defect of thinkpad X61:
Here is the test procedure:
set X61 power scheme to be Maximum performance and always use AC adapter.
Download Intel® Processor Identification Utility to test the CPU (T7500, 2.2G) of my thinkpad X61.
Here is the download link: http://support.intel.com/support/proces ... 014921.htm
Core 1 and Core 2 frequencies of T7500 are 2.2G when battery is installed even AC adapter unplugedd.
Core 1 and Core 2 frequencies of T7500 are dropped to be 1.19G and system bus frequency is dropped from 800 M to be 797 M when battery is removed !!
I tested another X61 of my friend, the CPU is T7300 (2G).
Core 1 and Core 2 frequencies of T7300 are also dropped to be 1.19G and system bus frequency is also dropped from 800 M to be 797 M when battery is removed !!
Furthermore, I tested a X60 of my friend, It does not have the defect !!


My thinkpad X61 (CPU: T7500 2.2G, 4M L2 cache, 800m FSB; RAM: Hynix 2G DDR2 P5300 667M 200 pin SODIMM, I added a Transcend 2G RAM stick; Hard drive: 160G 7200 RPM, 8 cell Li battery).

[anselnew]

I tried to reset the settings in power management of the BIOS, but nothing happened.

I think maybe This 65W Adapter may not be adequate to run the chip at max. clock speed.

I used a software : super_pi_mod-1.5 (http://www.xtremesystems.com/pi/) to test the CPU speed.


1M digits: with battery installed: 20 seconds, without battery installed: 40 seconds


Thanks.

[artic_squirrel]

yeah actually i can see with cpu-z when i get ac+battery,

t8300@ 2.4 GHz (max of course)

when i get only battery:

t8300@ 2.4GHz (max)


when i get only the ac adapter:

t8300@ 1.2 GHz (max)


but i think it's intel's fault, since if i disable the thinkpad power manager, and use rm clock, i can go up to 2.4 GHz on ac power

[SHoTTa35]

it's part of the design of the laptop. There are cases when the AC adapter can't provide enough power to the system by itself. The battery if plugged in would compensate then. If you remove the battery the BIOS locks the system down to lower power so you don't undervolt and fry the CPU and other components of their needed power during the spiked usage.