1420638 - mac os default theme vibrancy may increase power usage

Status: NEW

(Core :: Graphics, enhancement, P3)

Description

[Ben Kelly [:bkelly, not reviewing]]

It seems that the default theme increases CPU and battery usage on mac.  The theory is this is due to the vibrancy in the theme.

Splitting this off from bug 1404042 since that seems to be focusing on display scaling now.

I took a couple profiles scrolling a page with default theme and light theme.

Light theme:

https://perfht.ml/2i5kKtw

Default theme:

https://perfht.ml/2i6e4Ly

These were taken scrolling:

https://remysharp.com/2017/11/24/binary-strings

The rasterization definitely seems worse, but I don't understand why.

Comment 1

[Ben Kelly [:bkelly, not reviewing]]

Actually, I may have been comparing start of fling in one case and mid-fling in the other case.  I guess the profiles in comment 0 don't show much of a difference.

Keeping this bug open for investigation of the theme vibrancy issue in general, though.

Comment 2

[Markus Stange [:mstange]]

I'm tweaking the summary to mention power usage instead of CPU usage. There's no evidence at all that vibrancy increases CPU usage - the blurring work that the window server has to do happens on the GPU, not on the CPU. We also haven't seen any evidence that it has a non-trivial impact on power usage, but we haven't gathered any numbers about it either.

Comment 3

[Daniel Holbert [:dholbert]]

(In reply to Markus Stange [:mstange] from comment #2)
> I'm tweaking the summary to mention power usage instead of CPU usage.

(Then it's out-of-scope for [qf] then, I think -- marking [qf-].)