CPU Utilization metrics not matching

Question

Hi,
I'm using c5d.2xlarge EC2 instance.
When compared CPU metrics from Cloudwatch with top command, they are not matching.

Even though the top command shows around 90% of CPU utilization, in the cloudwatch it is showing around 26% only.

Could you please help me with this

Accepted Answer

The `c5d.2xlarge` instance type has 8 vCPUs. `top` will report CPU usage as a percentage of a single CPU. You can press `I` (shift + i, capital I) to toggle Irix mode, which is explained as:

```
    1. %CPU  --  CPU Usage
       The task's share of the elapsed CPU time since the last screen
       update, expressed as a percentage of total  CPU  time.   In  a
       true  SMP environment, if 'Irix mode' is Off, top will operate
       in 'Solaris mode' where a task's cpu usage will be divided  by
       the  total  number  of  CPUs.  You toggle 'Irix/Solaris' modes
       with the 'I' interactive command.
```

Otherwise, you can press `1` within top to show a break down of all the CPUs. This should give you data that is closer to what CloudWatch shows.

CPU Utilization metrics not matching

Relevant content