Two observations on openMSX on Mac

By rolandve

Expert (113)

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24-06-2016, 22:07

Running openmsx from the terminal throws the following warnings:

"openmsx[16342:1034176] 16:14:16.673 WARNING: 140: This application, or a library it uses, is using the deprecated Carbon Component Manager for hosting Audio Units. Support for this will be removed in a future release. Also, this makes the host incompatible with version 3 audio units. Please transition to the API's in AudioComponent.h."

and the energy/processor usage is considerable. It uses about 50% cpu (1.7 Ghz, I7) while running at 100% msx speed. It will drain the battery of the laptop in about 3 hours while the msx machine is just looking at the msx-dos prompt.

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By Manuel

Ascended (15750)

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24-06-2016, 22:40

The first thing is mostly due to the SDL 1.2 library that openMSX is using. It's not easy to migrate to a newer one, but it's planned.

Did you try to change the renderer from SDL to SDLGL-PP? That should save a considerable amount of CPU usage, as all drawing will be done by the GPU then.

By rogermm

Master (130)

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25-06-2016, 00:09

Manuel wrote:

The first thing is mostly due to the SDL 1.2 library that openMSX is using. It's not easy to migrate to a newer one, but it's planned.

Did you try to change the renderer from SDL to SDLGL-PP? That should save a considerable amount of CPU usage, as all drawing will be done by the GPU then.

I dind't know about the SDLGL-PP renderer! Since I have 2 processors(Z80 and ARM) running on MSX-ARM simulator, this configuration will help improve the overall performance(openmsx run as a high priority thread, it slow down the overral performance). It appears it isn't the default configuration on Catapult! Is there a collateral effect on openmsx, using this setup ? latency ?

By Manuel

Ascended (15750)

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24-06-2016, 23:51

By wouter_

Champion (418)

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25-06-2016, 09:02

rolandve wrote:

... while the msx machine is just looking at the msx-dos prompt.

To a certain degree it doesn't really matter what the MSX is doing. A seemingly 'idle' msx-dos prompt is probably (I didn't check) in a loop polling for keyboard input. Emulating that might be just as hard as emulating a complex game or demo.

You can look at the performace tuning section in the manual for hints on how to improve emulation performance. Of those hints, as Manuel already said, the renderer setting has the largest impact.

By uberjack

Master (216)

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26-06-2016, 09:23

rolandve wrote:

and the energy/processor usage is considerable. It uses about 50% cpu (1.7 Ghz, I7) while running at 100% msx speed. It will drain the battery of the laptop in about 3 hours while the msx machine is just looking at the msx-dos prompt.

I regularly experience similar performance with CocoaMSX on my laptop, which is why I rarely run battery-draining tasks while on battery power Smile. I get better performance on my Mac Mini, but that's probably because of the (marginally) better video card.

Emulation is resource-intensive in any state, so you may want to pause the emulator when you're not actually using it.

By Vampier

Prophet (2297)

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27-06-2016, 06:12

uberjack wrote:

Emulation is resource-intensive in any state, so you may want to pause the emulator when you're not actually using it.

I live in California and my i5 minimac only uses about 4% cpu Wink

By uberjack

Master (216)

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28-06-2016, 06:29

Vampier wrote:

I live in California and my i5 minimac only uses about 4% cpu Wink

Smile Awesome, where exactly? I'm in Los Angeles.