Why QEMU the slowest emulator in the world?

About Qemu-system-ppc, a PPC Mac emulator for Windows, macOS and Linux that can run Mac OS 9.0 up to Mac OS X 10.5

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MicroApple
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Why QEMU the slowest emulator in the world?

Post by MicroApple »

I installed Mac OS 9.0.4 but QEMU is very slow at everything. What can I do to stop that slowness?
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Cat_7
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Re: Why QEMU the slowest emulator in the world?

Post by Cat_7 »

Why QEMU the slowest emulator in the world?
You know them all? ;-)

There is not much you can do. Qemu aims to be accurate, and so you can run almost every program that fits within its limitations.
The ppc emulation cannot make use of the acceleration available when the host uses the same architecture as the guest.

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gaetano
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Re: Why QEMU the slowest emulator in the world?

Post by gaetano »

I've been using the qemu-hardfloat-screamer version and the sound works intermittently, very strange because it worked very well before (now it asks for microphone allowance in privacy). :shock:
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Cat_7
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Re: Why QEMU the slowest emulator in the world?

Post by Cat_7 »

Has something changed on your host? What does intermittent mean in this case? You have drop-outs, slowness, or does sound sometimes not work at all?

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adespoton
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Re: Why QEMU the slowest emulator in the world?

Post by adespoton »

Probably also worth asking what changed in your setup? Sounds like you're on macOS; are you on macOS 11 beta by any chance?
gaetano
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Re: Why QEMU the slowest emulator in the world?

Post by gaetano »

Lowered the RAM to 768 and now it works perfectly again. Apparently, when you set the RAM to 1GB and virtual memory gets disabled because of it, the sound stops working almost completely (just one or two beeps of a sound and then nothing).
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Cat_7
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Re: Why QEMU the slowest emulator in the world?

Post by Cat_7 »

Yes,

The sound-enabled builds can only run with less than 1024Mb. After all, they are experimental ;-)

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phed
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Re: Why QEMU the slowest emulator in the world?

Post by phed »

Cat_7 wrote: Mon Oct 05, 2020 7:37 am
Why QEMU the slowest emulator in the world?
You know them all? ;-)

There is not much you can do. Qemu aims to be accurate, and so you can run almost every program that fits within its limitations.
The ppc emulation cannot make use of the acceleration available when the host uses the same architecture as the guest.

Best,
Cat_7
So far, I found some programs that can be run in SheepShaver, but does not run in qemu-system-ppc-screamer.

Colibricks
https://macintoshgarden.org/games/colibricks-13

PacMan Deluxe
https://macintoshgarden.org/games/pacmac-deluxe

Sixtyforce 0.8.0
https://macintoshgarden.org/apps/sixtyforce

Rosetta Stone
https://macintoshgarden.org/apps/rosetta-stone-chinese
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adespoton
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Re: Why QEMU the slowest emulator in the world?

Post by adespoton »

phed wrote: Fri Dec 25, 2020 3:59 am
Cat_7 wrote: Mon Oct 05, 2020 7:37 am
Why QEMU the slowest emulator in the world?
You know them all? ;-)

There is not much you can do. Qemu aims to be accurate, and so you can run almost every program that fits within its limitations.
The ppc emulation cannot make use of the acceleration available when the host uses the same architecture as the guest.

Best,
Cat_7
So far, I found some programs that can be run in SheepShaver, but does not run in qemu-system-ppc-screamer.

Colibricks
https://macintoshgarden.org/games/colibricks-13

PacMan Deluxe
https://macintoshgarden.org/games/pacmac-deluxe

Sixtyforce 0.8.0
https://macintoshgarden.org/apps/sixtyforce

Rosetta Stone
https://macintoshgarden.org/apps/rosetta-stone-chinese
When you say "does not run", what is the error you get? Which QEMU options are you using? Which OS version are you running? In all likelihood, the software will not run on real hardware with the configuration you currently have set -- although if you're using the fastfpu build of Screamer, it could also be an FPU issue.
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Cat_7
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Re: Why QEMU the slowest emulator in the world?

Post by Cat_7 »

Colibricks works, you just need to disable the screen enhancement setting.
Pacman and perhaps also Rosetta stone suffer from not be able to load the gamma tables for the monitor.
Sixtyforce (i tested 0.6 earlier) works, but runs a 1-2 frames a second....

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Cat_7
spiral_pof
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Re: Why QEMU the slowest emulator in the world?

Post by spiral_pof »

can iyou build qemu to make it as fast as exagear
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Cat_7
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Re: Why QEMU the slowest emulator in the world?

Post by Cat_7 »

Hi,

Sorry, there is not much we can do. We only build the software from the source that is maintained and developed by others.

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Cat_7
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