Lenovo laptop with Intel CPU remains at lowest clock

Question

I have an Lenovo T440p with an Intel Core i5 4300M CPU. 8GB RAM, SSD running with Windows 7 (preinstalled).

The only thing I did not like about this laptop was the screen, which I replaced (the whole LCD unit - including the hinges) with a full-hd version. It was rather easy; I did not have to remove the CPU/GPU.

Recently I noticed is that the laptop has become really slow, especially running VMs. In task manager I can see that the CPU is many times at 100% on all cores. CPU-Z is reporting that the CPU is running at the lowest possible clock:

• Core Speed: 798.85 MHz
• Multiplier x8
• Bus Speed 99.87 MHz
• Core Voltage of 0.659 V

(full details at the end)

I have set Windows already to "Maximum Performance" in the energy settings. I have also taken out the battery and am running with the power adapter. I also set the Lenovo Power Manager to maximum performance. Sadly, no improvement.

What else can I try?

Processors Information
-------------------------------------------------------------------------

Processor 1         ID = 0
    Number of cores     2 (max 8)
    Number of threads   4 (max 16)
    Name            Intel Core i5 4300M
    Codename        Haswell
    Specification       Intel(R) Core(TM) i5-4300M CPU @ 2.60GHz
    Package (platform ID)   Socket 947 rPGA (0x4)
    CPUID           6.C.3
    Extended CPUID      6.3C
    Core Stepping       C0
    Technology      22 nm
    TDP Limit       37.0 Watts
    Tjmax           100.0 °C
    Core Speed      799.0 MHz
    Multiplier x Bus Speed  8.0 x 99.9 MHz
    Stock frequency     2600 MHz
    Instructions sets   MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, EM64T, VT-x, AES, AVX, AVX2, FMA3, TSX
    L1 Data cache       2 x 32 KBytes, 8-way set associative, 64-byte line size
    L1 Instruction cache    2 x 32 KBytes, 8-way set associative, 64-byte line size
    L2 cache        2 x 256 KBytes, 8-way set associative, 64-byte line size
    L3 cache        3 MBytes, 12-way set associative, 64-byte line size
    FID/VID Control     yes


    Turbo Mode      supported, enabled
    Max non-turbo ratio 26x
    Max turbo ratio     33x
    Max efficiency ratio    8x
    O/C bins        none
    Ratio 1 core        33x
    Ratio 2 cores       32x
    Ratio 3 cores       32x
    Ratio 4 cores       32x
    TSC         2596.8 MHz
    APERF           794.7 MHz
    MPERF           2581.1 MHz
    IA Voltage Mode     PCU adaptive
    IA Voltage Offset   0 mV
    GT Voltage Mode     PCU adaptive
    GT Voltage Offset   0 mV
    LLC/Ring Voltage Mode   PCU adaptive
    LLC/Ring Voltage Offset 0 mV
    Agent Voltage Mode  PCU adaptive
    Agent Voltage Offset    0 mV

    Temperature 0       55°C (131°F) [0x2D] (Core #0)
    Temperature 1       59°C (138°F) [0x29] (Package)
    Power 0         11.12 W (Package)
    Power 1         1.54 W (IA Cores)
    Power 2         0.24 W (GT)
    Power 3         9.34 W (Uncore)
    Power 4         0.88 W (DRAM)
    Voltage 0       0.66 Volts (VID)
    Voltage 1       +0.00 Volts (IA Offset)
    Voltage 2       +0.00 Volts (GT Offset)
    Voltage 3       +0.00 Volts (LLC/Ring Offset)
    Voltage 4       +0.00 Volts (System Agent Offset

)

Answer 1

After many trial & error attempts, I found out what the issue was: My Laptop (cannot confirm if all Lenovo Laptops have this behavior) will throttle the CPU to the lowest setting if no battery is plugged-in. I don't know what the fine Lenovo engineers have been thinking...

Answer 2

Disable Hyperthreading on the BIOS - you will lose your 2.4 turbo clock but it will not be throttled down to 800Mhz!