AMD vs Intel - Firefox performance


I’m just wondering. Does performance on Intel differ from AMD? I have two machines, both running current versions of unstable. Both are running KDE, and both are running firefox-55.0.2_1,1.

My desktop has

hw.model: AMD Phenom™ II X4 840 Processor (3.2 GHz)
hw.ncpu: 4
hw.realmem: 17179869184
nvidia graphics

The laptop has

hw.model: Intel® Core™ i5-3320M CPU @ 2.60GHz
hw.ncpu: 4
hw.realmem: 8589934592
intel graphics

One thing I have noticed is that firefox uses vastly more cpu on my AMD desktop than the laptop. I have the same addons running on both:

  • Lastpass
  • NoScript
  • Panorama Tab Group Name
  • Privacy Badger
  • Self-destructing cookies
  • Tab groups
  • Tab Mix Plus
  • uBlock Origin

However, on the AMD box, I am showing a SIZE in top of 47815M and a WCPU of 150.81%, and I have to restart every few days. On the laptop (intel), the SIZE is 1857M and the WCPU is 6.78%, and I almost never have to restart. Now the desktop box has 71 tabs open, while the laptop has 36 open. While there are significantly more open on the desktop, it should not be enough to account for 25 times the cpu usage or memory usage.

Is this endemic to AMD-vs-Intel, or am I missing something? At one point, I thought it may be something like a memory leak among my plugins, but then I would think that the behavior would be similar on both the laptop and desktop.



A sample of one with dissimilar workload isn’t enough to really say it’s a system thing. How do you know you didn’t have a tab open that’s throwing a bunch of Javascript errors or thrashing the network? If you are doing things in a browser, you would need to have a controlled opening of all the tabs one at a time and know EXACTLY what content is being sent. (not even going to talk about add-ons :stuck_out_tongue: )

  • If it’s an AMD problem, you will see it in other applications. Can you compare a different application on both platforms and see if you encounter similar results?
  • Try chrome or iperf or nc and see if you are having problems with the network on the AMD box. Poor driver performance is a thing sometimes. isolating it and diagnosing it is impossible without your help. :slight_smile:
  • Have you tried opening 71 tabs on the laptop? Perhaps firefox hit a threshold that is causing problems?
  • Do you see the same poor behaviour at 36 tabs on the Desktop? Again, without controlled data, you can’t really claim anything. You could also try closing tabs and see if the issue goes away?

If you could isolate the issue that’s causing the high cpu it would help to diagnose it. Since they seem to be your working systems, monitor the AMD as you start things up.



My Firefox with some 300 tabs is currently idling at 60% CPU and around 10GB of memory (TrueOS Stable) I would restart but I have a paused BSD Now Video. I seem to have read somewhere that Firefox leaks memory on the BSDs and needs some memory allocator changes. You could open about:memory and see if anything shows up. Also there is a setting that shows background Javascripts that are running; these appear to persist even when the tab for the site is closed (sorry forgot how to get to this)