X
Tap here to go to the mobile version of the site.

Support Forum

What does dom.maxHardwareConcurrency 16 Mean

Posted

What does dom.maxHardwareConcurrency 16 mean?

What does dom.maxHardwareConcurrency 16 mean?

Chosen solution

Just leave the pref(s) at their default value. This is not an important feature and best is usually not to modify prefs unless there is a problem with some feature.

Read this answer in context 1

Additional System Details

Installed Plug-ins

  • Shockwave Flash 26.0 r0

Application

  • User Agent: Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:55.0) Gecko/20100101 Firefox/55.0

More Information

cor-el
  • Top 10 Contributor
  • Moderator
17573 solutions 158946 answers

Helpful Reply

See: *https://developer.mozilla.org/en-US/Firefox/Releases/48#DOM_HTML_DOM *https://developer.mozilla.org/en-US/docs/Web/API/NavigatorConcurrentHardware ---- https://dxr.mozilla.org/mozilla-release/source/modules/libpref/init/all.js#5664 <pre><nowiki>// return the maximum number of cores that navigator.hardwareCurrency returns pref("dom.maxHardwareConcurrency", 16);</nowiki></pre>

Question owner

Thank you.

It looks like it means the number of threads that can be run at the same time. In my case 16. Presumably this means 1 to 16. Am I correct?

Thank you. It looks like it means the number of threads that can be run at the same time. In my case 16. Presumably this means 1 to 16. Am I correct?
cor-el
  • Top 10 Contributor
  • Moderator
17573 solutions 158946 answers

The pref defines a maximum of how many logical cores for workers are available. If you have a configuration that supports more logical cores then Firefox will report the maximum as set via the pref.

You can inspect the current setting via the navigator object in the Web Console.

  • window.navigator.hardwareConcurrency

If you regularly would visit website that makes excessive use or workers then you may want to set this pref to a lower value.


The pref defines a maximum of how many logical cores for workers are available. If you have a configuration that supports more logical cores then Firefox will report the maximum as set via the pref. You can inspect the current setting via the navigator object in the Web Console. *window.navigator.hardwareConcurrency If you regularly would visit website that makes excessive use or workers then you may want to set this pref to a lower value. ---- *https://developer.mozilla.org/en-US/docs/Web/API/NavigatorConcurrentHardware/hardwareConcurrency

Question owner

I do not see this (window.navigator...) in about:config

I see: dom.maxHardwareConcurrency 16

I do not co-work

I do not see this (window.navigator...) in about:config I see: dom.maxHardwareConcurrency 16 I do not co-work
cor-el
  • Top 10 Contributor
  • Moderator
17573 solutions 158946 answers

Helpful Reply

window.navigator is not in about:config, but is JavaScript code that you can run in the Web Console like I wrote above.

window.navigator is not in about:config, but is JavaScript code that you can run in the Web Console like I wrote above. *"3-bar" menu button or Tools -> Web Developer *https://developer.mozilla.org/en/Tools/Web_Console

Question owner

I am lost

I am lost
cor-el
  • Top 10 Contributor
  • Moderator
17573 solutions 158946 answers

Are you able to open the Web Console (Ctrl+Shift+K)?

On its command line (>>) you can paste the JavaScript code. Press the Enter key to evaluate the code and see the result.

  • window.navigator.hardwareConcurrency
Are you able to open the Web Console (Ctrl+Shift+K)? On its command line (>>) you can paste the JavaScript code. Press the Enter key to evaluate the code and see the result. *window.navigator.hardwareConcurrency *https://developer.mozilla.org/en-US/docs/Web/API/Navigator

Modified by cor-el

Question owner

I could not find the command line, but, with your help, I have found it >>.

I see: window.navigator.hardwareConcurrency 2

So, it looks like two people could work at the same time. However, I work alone. Does this mean the processor has two cores for independent processing?

Best wishes

PS. Does the command line look at all JavaScript code in the Firefox browser, or all JS code in kubuntu (my OS). Does this command line have other functions?

I could not find the command line, but, with your help, I have found it >>. I see: window.navigator.hardwareConcurrency 2 So, it looks like two people could work at the same time. However, I work alone. Does this mean the processor has two cores for independent processing? Best wishes PS. Does the command line look at all JavaScript code in the Firefox browser, or all JS code in kubuntu (my OS). Does this command line have other functions?

Question owner

PS in about:config it is set to 16! (dom.maxHardwareConcurrency 16)

PS in about:config it is set to 16! (dom.maxHardwareConcurrency 16)
cor-el
  • Top 10 Contributor
  • Moderator
17573 solutions 158946 answers

dom.maxHardwareConcurrency sets the maximum, so if you would have a very sophisticated CPU that would support 32 cores then websites can only use 16. What navigator.hardwareConcurrency reports is what websites detect and what is safe to use.

If you set dom.maxHardwareConcurrency to 1 and close and restart Firefox then you will see that navigator.hardwareConcurrency will report 1.

dom.maxHardwareConcurrency sets the maximum, so if you would have a very sophisticated CPU that would support 32 cores then websites can only use 16. What navigator.hardwareConcurrency reports is what websites detect and what is safe to use. If you set dom.maxHardwareConcurrency to 1 and close and restart Firefox then you will see that navigator.hardwareConcurrency will report 1.

Question owner

I have an old pc and the processor is basic. I believe that it is dual core,

Would you advise changing the HardwareConcurrency in about:config to 2, or leave it at 16.

Thanks

I have an old pc and the processor is basic. I believe that it is dual core, Would you advise changing the HardwareConcurrency in about:config to 2, or leave it at 16. Thanks
cor-el
  • Top 10 Contributor
  • Moderator
17573 solutions 158946 answers

Chosen Solution

Just leave the pref(s) at their default value. This is not an important feature and best is usually not to modify prefs unless there is a problem with some feature.

Just leave the pref(s) at their default value. This is not an important feature and best is usually not to modify prefs unless there is a problem with some feature.

Question owner

Thank you for all the help.

Best wishes.

Thank you for all the help. Best wishes.