March 3, 2023

Making sense of htop's load average metrics

![[Pasted image 20230528145043.png]]

The 3 numbers

In htop, you'll notice that there are 3 numbers in Load Average:

Load average: 0.72 0.36 0.14

These 3 numbers, from left to right, are load averages across:

1. 1 minute timespan
2. 5 minute timespan
3. 15 minute timespan

What does the load number mean

It basically means how many cores are being used, and at what capacity.

Every core adds 1.0 to your computer's load handling capacity.

Suppose you have a single core.

So, your total load capacity is 1.0 x 1 = 1.0

So, here are some scenarios:

• Load average = 0.5
  • The cpu is being used at half capacity. 50% usage.
• Load average = 1.0
  • The cpu is being used at full capacity. 100% usage.
• Load average = 1.2
  • The cpu is already being used at full capacity. Even then, 0.2 load is not being handled (excess)
  • Your tasks are heavier than what the cpu can handle. 0.2 more than wha the computer can handle. Now, suppose you have 4 cores.

So, your total load capacity is 1.0 x 4 = 4.0

• Load average = 0.5
  • One core is being used at half capacity. The remaining 3.5 capacity is unused (on average).
• Load average = 1.0
  • Your workload is equal to one core's capacity. You can still take on 3.0 of load (on average).
• Load average = 3.0
  • Your workload is equal to 3 core's capacity. You still have spare room for 1.0 of load (on average) (this is one core equivalent of load)
• Load average = 4.0
  • Your workload is using all four cores at 100% capacity (on average).
• Load average = 5.0
  • Your workload is using all four cores at 100% capacity. On top of that, a workload of 1.0 (equivalent to one core) is waiting to be processed.
  • Basically, you need one more core to handle this much load and not get overloaded.

So now, looking again at the screenshot:

![[Pasted image 20230528145106.png]]

It shows that I have 12 cores (numbered 0 to 11). So my computer can take upto 12.0 load. Any load exceeding that will have to wait.

The load averages are:

• 1 minute: the load averaged 0.72
  • So, in the last minute, my computer could have handled 12 - 0.72 = 11.28 more load (on average).
• 5 minutes: the load averaged 0.36
  • So, in the last 5 minutes, my computer could have handled 12 - 0.36 = 11.54 more load (on average).
• 15 minutes: the load averaged 0.14
  • So, in the last 15 minutes, my computer could have handled 12 - 0.14 = 11.86 more load (on average).

Ending notes

That's it. Every core adds 1.0 to your computer's load capacity.

Now look at your htop, and see how much load your computer is handling, and how much more load your computer can take.