Github actions have inconsistent CPU and IOPS

Do the underlying machines that the GitHub Actions inconsistent in the specs that they have?

Given a random set of runs, we sometimes see runners be assigned to machines that have half the IOPS (and less CPU) than other machines. Here is an example:

4284 438
4126 394
2609 338 Stall
3870 369
4329 442
2548 339 Stall

This manifests in our test suite as the tests sometimes taking 2x as long to run.

Hi @rodeoclash,

Could you please let me know which hosted runner did you use?
And what command to get the IO/CPU data?



I’m not sure how to answer the question about which runner (we used the GitHub hosted ones), but the bench marks were done using sysbench.

sudo apt-get install -y sysbench
sysbench --test=fileio --file-test-mode="seqwr" --file-total-size=128M run
sysbench --test=cpu --cpu-max-prime=20000 run

runs-on: 'ubuntu-latest'

Thanks @rodeoclash for your quick reply!

I tried the command on my side, and raised an internal ticket to confirm the appearance, I will update when there’s a response.


Hi @rodeoclash,

Could you please provide the repo owner/name info here? Dev team will take further investigation.



If you’d like me to provide specific actions run logging which show the report for the iops being low, let me know.