[OpenJDK 2D-Dev] RFR: 8251854 [macosx] Java forces the use of discrete GPU

[Kevin Rushforth]

> This is how other applications work...
>  Also results are similar to other macbooks without discrete graphics.

That's sort of what I was getting at with my earlier question: why have 
a discrete graphics card that never / seldom gets used? This may be more 
of a question for Apple, but it seems quite strange to me.

If it switched automatically based on whether or not you were on 
battery, or some user setting that favored lower power usages over 
increased performance, then it would make sense. As it is, I'm having a 
hard time understanding the motivation.

I haven't tested an FX app yet, but since this changes the plist 
properties, I want to see whether or not FX apps are impacted.

-- Kevin


On 8/25/2020 4:01 PM, Sergey Bylokhov wrote:
> On 25.08.2020 15:40, Philip Race wrote:
>> On 8/25/20, 12:27 PM, Sergey Bylokhov wrote:
>>> On 25.08.2020 05:43, Kevin Rushforth wrote:
>>>> Does this only apply when the MacBook is running on battery, or 
>>>> will this affect performance even when the laptop is plugged in? If 
>>>> the latter, I wonder what Apple's rationale is for including a 
>>>> discrete graphics card that isn't used most of the time.
>>
>> Based on the numbers, I wonder if we should make this change ?
>
> This is how other applications work, some numbers are now aligned to 
> the metal pipeline.
> Also results are similar to other macbooks without discrete graphics.
>
>>> It is applied if the "automatic graphics switching" is enabled, if 
>>> the user disables
>>> this feature for the "power adapter" mode, then the discrete 
>>> graphics will be always used.
>>
>> That's a bit misleading
>> If I disable automatic graphics switching it is disabled for BOTH 
>> batter and power
>> and vice versa. In other words there is no way to express that 
>> battery power should fall back
>> to integrated and that you only want discrete when running on the 
>> adapter.
>
> It is possible to do it manually, in the "power adapter" mode the user 
> can disable
> "automatic graphics switching", and enable it in the "battery" mode.
>
> BTW I have never did it myself.
>