Periodic framerate drop on a mac

radiodario

Periodic framerate drop on a mac

in Integration and Hardware • 2 years ago

Dear fellow procesiites:

I've writen quite a complex app in processing. It's desinged as a systems monitor that is run on a big screen in the offices of the company I work for. it features rich graphics and real time updates using websockets.

Everything runs fine on my computer (MacBook Pro 13' core i7 with 4gb of ram). However, when I run the program on the monitor computer (a Macbook Pro 15' core i7 with 8GB of ram, running the same version of mac os, java and processing) the framerate oscillates. It runs fine at 24 fps and then after a bit it periodically drops to around 12. This happens periodically, but I am unsure as to why it should run fine on my computer but not so well on a higher spec model.

I've profiled my app on netbeans and as far as I can tell, there aren't any obvious memory leaks (memory usage oscillates at around 75 mb, allocated memory is at around 90 mb. Could it be something to do with the garbage collector? Any ideas would be massively appreciated.

cheers

Dario

:wq

Replies(3)

radiodario

Re: Periodic framerate drop on a mac

2 years ago

Aha!

i think i've found the reason. My dev computer has the intel HD integrated graphics card. The other macbook has both the integrated intel card and an AMD Radeon HD 6490M. I tried the excellent app gfxCardStatus app that lets you switch between the two cards and i found that on the Radeon, it shows the framerate drop while on the intel there is none.

the app uses JAVA2D

any ideas? is there a known issue with the Radeons?

cheerio

PhiLho

Re: Periodic framerate drop on a mac

2 years ago

First time I hear the graphics card can cause such behavior. Interesting.
Note that Java 2D (the Java back end used by Processing) can use hardware acceleration, but it can be dependent on the card / the driver. Maybe if we have no hardware acceleration, it has to generate more objects to achieve the drawing, so generate more garbage to be collected, making more significant pause.
A possible way to avoid this (untested, not sure if reliable) might be to trigger collection more often. With less garbage to collect, the pauses might be less noticeable.

radiodario

Re: Periodic framerate drop on a mac

2 years ago

I added frequent calls to runtime.gc() and it still hasn't made any difference. I think it's to do with the driver update from apple to enable switching between graphics cards. or something like that...

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