pagespeed.web.dev lighthouse scores are off because CPU/Memory Power levels are not correct

Open JoelLisenby opened this issue 1 year ago • 1 comments

I wanted to confirm that this does appear to be the case, see evidence below:

Pagespeed insights CPU/Memory Power = 274 Lighthouse (Linux CLI) CPU/Memory Power = 3670 Lighthouse (Google Chrome Dev Tools) CPU/Memory Power = 3509

Pagespeed Insights at https://pagespeed.web.dev/:

Lighthouse scores in headless lighthouse on ubuntu server (cli, WSL2 in Windows 11):

Lighthouse scores in Google Chrome dev tools:

Originally posted by @JoelLisenby in https://github.com/GoogleChrome/lighthouse/issues/12083#issuecomment-2375452955

Sep 25 '24 23:09 JoelLisenby

Just to add to this, we ran a test today and are seeing Mobile scores of 93 on lighthouse locally and 53 on pagespeed.web.dev. 40 points difference, yikes! Makes sense though when the CPU / Memory throttle is simulating a device over 13X slower on pagespeed.web.dev.

Sep 26 '24 00:09 JoelLisenby