1243297 - Multiprocessor off and NewNon-e10s tab(from a default nightly - multiprocessor on) behaves diferently

Status: RESOLVED WONTFIX

(Core :: DOM: Content Processes, defect)

Description

[Adrian Florinescu [:aflorinescu]]

Description:
The FF Nightly 46 with multiprocessor off behaves differently than using a  New Non-E10s tab from a Nightly 46 with multiprocessor on.

Steps:
1. Open FF Nightly 46.
2. Open https://greensock.com/js/speed.html 300dots and run test.
3. Open Menu and select New Non-E10s tab and rerun https://greensock.com/js/speed.html 300dots.
4. Open FF Nightly 46 /Preferences - uncheck multiprocessor, restart browser and rerun https://greensock.com/js/speed.html 300dots.

Actual Result:
Based on your system configuration the FPS results should look like this:
2: x FPS                 (e.g: 20FPS)
3: x +/- 10%x FPS        (e.g: 22FPS)
4: 2x FPS                (e.g: 40FPS)
where x varies depending on your hardware configuration

The drop in performance and differences are already recorded in Bug1241165 and Bug1242969.


Expected Result:
My take on this is that the NewNon-e10s tab(from a Nightly46 default) should function nearly identical or at least in the close vicinity with how the browser behaves in the state of Multiprocessor set to off.

Comment 1

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

"New non-e10s window" will always be imperfect. There are certain things that must be set process-wide, like whether OMTC is enabled. I suspect this bug has to do with something like that.

In any case, "New non-e10s window" is a temporary thing for testing only that will go away soon. We probably wouldn't spend much time on it at this point.