On my Ubuntu 16.04, I am running a program that is relatively expensive in terms of CPU usage. It takes quite much time to finish, and other tasks (like browsing the web) get slower as a consequence. I was looking for a way to improve the computing power, if possible and at the same time to know better what is happening in my laptop.

By this, I found that, if I ask top, the program I am running shows a CPU usage of 100%, while when I open the System monitor the CPU usage is only at ~25% in the Processes tab. In addition, the Resources tab in System monitor shows 4 CPUs, whose usage changes from ~5 to ~100% for each one:

The outcome of lscpu is:

@C:~$ lscpu

Architecture:          x86_64

CPU op-mode(s):        32-bit, 64-bit

Byte Order:            Little Endian

CPU(s):                4

On-line CPU(s) list:   0-3

Thread(s) per core:    2

Core(s) per socket:    2

Socket(s):             1

NUMA node(s):          1

Vendor ID:             GenuineIntel

CPU family:            6

Model:                 142

Model name:            Intel(R) Core(TM) i5-7200U CPU @2.50GHz

Stepping:              9

CPU MHz:               3099.937

CPU max MHz:           3100,0000

CPU min MHz:           400,0000

BogoMIPS:              5423.81

Virtualization:        VT-x

L1d cache:             32K

L1i cache:             32K

L2 cache:              256K

L3 cache:              3072K

NUMA node0 CPU(s):     0-3

Is there anything I can do to improve the situation, such as dilute the work among the 4 CPUs? Usinge nice does not seem a solution to my situation.

I know this may be a general question that depends on the type of program I am running (let's say it is a Python script), but I am trying here to get general knowledge.