Speed Up a Slow Linux PC: Check CPU, Services, Memory, and Disk I/O

Before accelerating a Linux computer, you need methods to locate boot-time services, processes running at various priorities, CPU status, memory usage, swap fullness, and disk health.

1. Check CPU Information

The first step to speed up a sluggish Linux machine is to examine CPU details; a slow LibreOffice experience often stems from insufficient CPU speed.

Open a terminal and run one of the following commands:

cat /proc/cpuinfo

lscpu

The commands display detailed CPU information such as vendor_id, model name, CPU MHz, cache size, microcode, and bogomips.

bogomips: a bogus measure of millions of instructions per second, indicating system performance.

model_name: shows the CPU manufacturer, model, and speed (e.g., 1.73 GHz Intel Celeron).

CPU MHz: measures the internal clock speed (e.g., 1733.329 MHz).

An Intel Celeron 1.73 GHz CPU is low‑performance compared to a multi‑core 2.8 GHz CPU, which can cause slow application performance.

Solution

If the CPU is old and slow, the only remedy is to replace it with a newer processor.

2. Check Boot‑Time Services

Various commands can list services that start at boot:

service --status-all

chkconfig --list

initctl list

For systemd‑based distributions, use: sudo systemctl list-unit-files --state=enabled Solution

On systemd systems, manage services with systemctl to prevent unwanted services from running at boot.

3. Check CPU Load

Use top to view processes consuming the most CPU. Identify and terminate offending processes with kill if necessary.

Solution

Close unused applications and prevent background programs you don’t need from running.

Install preload to keep frequently used applications cached in memory for faster startup:

sudo apt-get install preload

sudo yum install preload

4. Check Free Memory

Use the free command to view available idle memory. Low free memory can degrade performance.

Solution

Upgrade RAM or replace memory‑heavy applications (e.g., use AbiWord instead of LibreOffice).

5. Check Disk Usage

When the hard‑drive indicator blinks constantly, I/O may be the issue. Use iotop to diagnose disk I/O problems.

sudo apt install iotop

sudo yum install iotop

iotop

shows which processes are performing I/O, their throughput, and read/write speeds.

Conclusion

While many factors can slow a system, CPU, memory, and disk I/O are the primary culprits. Applying the methods described above helps pinpoint performance issues and provides actionable solutions.