Is there a way to make QEMU PPC faster?

[4-YearWindowsPro]

Hello, I've been thinking if I can make QEMU PPC fast, I tried everything.
Well, when I go with the memory towards 1008MB, It does an immediate kernel panic on boot.
Does anyone know how can i fasten it?

I've heard that Windows PPC is slow, but I can change the CPU model.
I did that, but it still takes 35secs to open an app. (Why?)

[mcayland]

Hello, I've been thinking if I can make QEMU PPC fast, I tried everything.
Well, when I go with the memory towards 1008MB, It does an immediate kernel panic on boot.
Does anyone know how can i fasten it?

I've heard that Windows PPC is slow, but I can change the CPU model.
I did that, but it still takes 35secs to open an app. (Why?)

35 secs to an open an app? That sounds completely broken: here on x86_64 the performance is good enough to provide a usable experience. Can you provide more information:

- What host architecture/OS are you using?
- What OS version are you attempting to boot? Where did you get the image from?
- What version of QEMU are you using? (The output of qemu-system-ppc -version)
- What is the exact command line that you are using?

[4-YearWindowsPro]

Hello, I've been thinking if I can make QEMU PPC fast, I tried everything.
Well, when I go with the memory towards 1008MB, It does an immediate kernel panic on boot.
Does anyone know how can i fasten it?

I've heard that Windows PPC is slow, but I can change the CPU model.
I did that, but it still takes 35secs to open an app. (Why?)

35 secs to an open an app? That sounds completely broken: here on x86_64 the performance is good enough to provide a usable experience. Can you provide more information:

- What host architecture/OS are you using?
- What OS version are you attempting to boot? Where did you get the image from?
- What version of QEMU are you using? (The output of qemu-system-ppc -version)
- What is the exact command line that you are using?

Windows 10 Enterprise 64bit
Mac OS X Tiger - Some guy on Internet Archive as a preinstalled qcow2 image
Screamer 7.2.50.0 (The crackle does not matter for me)
qemu-system-ppc-screamer -L pc-bios -boot c -M mac99 -m 1008 -hda osx-tiger_10.4.11_installed.qcow2 -cdrom walls.iso -cpu g3

[4-YearWindowsPro]

Hello, I've been thinking if I can make QEMU PPC fast, I tried everything.
Well, when I go with the memory towards 1008MB, It does an immediate kernel panic on boot.
Does anyone know how can i fasten it?

I've heard that Windows PPC is slow, but I can change the CPU model.
I did that, but it still takes 35secs to open an app. (Why?)

35 secs to an open an app? That sounds completely broken: here on x86_64 the performance is good enough to provide a usable experience. Can you provide more information:

- What host architecture/OS are you using?
- What OS version are you attempting to boot? Where did you get the image from?
- What version of QEMU are you using? (The output of qemu-system-ppc -version)
- What is the exact command line that you are using?

Windows 10 Enterprise 64bit
Mac OS X Tiger - Some guy on Internet Archive as a preinstalled qcow2 image
Screamer 7.2.50.0 (The crackle does not matter for me)
qemu-system-ppc-screamer -L pc-bios -boot c -M mac99 -m 1008 -hda osx-tiger_10.4.11_installed.qcow2 -cdrom walls.iso -cpu g3

"good" huh? Some apps don't even open! And I have even 8GB of RAM! The problem is allocating more than 1008MB for guest ram gives panics on boot. The memory limit is cuz Tiger did have a RAM limit, and that's because of more than that the addresses are scrambled and it can't find the right bank. This has been fixed since Snow Leopard because of changing the CPU vendor.

[Cat_7]

The problem is allocating more than 1008MB for guest ram gives panics on boot. The memory limit is cuz Tiger did have a RAM limit, and that's because of more than that the addresses are scrambled and it can't find the right bank. This has been fixed since Snow Leopard because of changing the CPU vendor.

That is not correct. You can run Tiger with sound and 2Gb memory.
You cannot run Mac OS 9 with sound and set memory to 1024 or higher.

Best,
Cat_7

[mcayland]

35 secs to an open an app? That sounds completely broken: here on x86_64 the performance is good enough to provide a usable experience. Can you provide more information:

- What host architecture/OS are you using?
- What OS version are you attempting to boot? Where did you get the image from?
- What version of QEMU are you using? (The output of qemu-system-ppc -version)
- What is the exact command line that you are using?

Windows 10 Enterprise 64bit
Mac OS X Tiger - Some guy on Internet Archive as a preinstalled qcow2 image
Screamer 7.2.50.0 (The crackle does not matter for me)
qemu-system-ppc-screamer -L pc-bios -boot c -M mac99 -m 1008 -hda osx-tiger_10.4.11_installed.qcow2 -cdrom walls.iso -cpu g3

"good" huh? Some apps don't even open! And I have even 8GB of RAM! The problem is allocating more than 1008MB for guest ram gives panics on boot. The memory limit is cuz Tiger did have a RAM limit, and that's because of more than that the addresses are scrambled and it can't find the right bank. This has been fixed since Snow Leopard because of changing the CPU vendor.

I've just done a quick test here with latest QEMU 8.2 upstream on a recent-ish x86 laptop running Linux with your same image and the command line below:

Code: Select all

qemu-system-ppc -hda osx-tiger_10.4.11_installed.qcow2 -M mac99 -m 512

The rough timings I see here are:

- Boot time from start to desktop is ~95s
- Opening applications such as "Chess" and "Safari" takes about 3-4s the first time, instant on subsequent tries

So something is definitely wrong in your setup. Things that could affect performance on your machine:

- Windows AntiVirus and NTFS tend to heavily penalise disk I/O: excluding the directory containing the qcow2 image from the antivirus may help
- Using a screamer build instead of a vanilla build may have a performance impact (I am not responsible for anything outside of QEMU upstream). 7.2 is also already a year old so you should try something newer.
- Don't override the CPU default with "-cpu g3". Each machine has its own defaults, so you should only override them if you really know what you're doing.
- I don't have easy access to Windows so there is much less testing there.

If you could try experimenting with the various options above and report back when you discover the problem with your setup, that would be greatly appreciated.

[Cat_7]

In addition to that, can you also tell us the specs of your host?

Best,
Cat_7

[adespoton]

From his comments, he's running a host with 8GB RAM. I switched from 8GB to 16GB in 2015; I can't imagine having less than 32GB for emulation and virtualization on x86 hardware today, especially if the host is running Windows 11.

8GB is the minimum RAM required for Windows 11, and I consider any memory used by emulators and virtual machines to be memory that has to be added "on top" of the minimum recommended memory.

So if my host OS recommends a minimum of 8GB, that means to run a QEMU image with 1GB RAM, the host needs a minimum of 9GB (which realistically means 16GB). If I plan to have a docker image running with 4GB RAM, a VMWare virtual machine with 4GB RAM and a QEMU image with 256MB RAM, that means I need a machine with 16GB PLUS 256MB of RAM, which means 32GB RAM.

If I plan to have Chrome open in the background while running all this, I DEFINITELY need 32GB RAM, especially if multiple tabs are open. Otherwise, the emulation will slow to a crawl as Windows 11 attempts to manage memory in a way that it is not optimized to do. And emulators like SheepShaver may not even launch correctly.

If all you've got is 8GB RAM, I'd recommend dual booting into a lightweight Linux such as Arch with xfce and running QEMU from there without any web browsers or multimedia apps open. If a browser MUST be open, use Firefox with uBlock Origin and NoScript installed, and limit the number of tabs loaded.

These are just my observations and suggestions though; I'm sure others are happily running Windows with 8GB RAM and various emulators with no issues -- but that likely has to do with what other hardware they've got and what other applications they're running.

[4-YearWindowsPro]

The problem is allocating more than 1008MB for guest ram gives panics on boot. The memory limit is cuz Tiger did have a RAM limit, and that's because of more than that the addresses are scrambled and it can't find the right bank. This has been fixed since Snow Leopard because of changing the CPU vendor.

That is not correct. You can run Tiger with sound and 2Gb memory.
You cannot run Mac OS 9 with sound and set memory to 1024 or higher.

Best,
Cat_7

Sorry, but I said if I set it higher than that, it'll give me a panic.

I found on Wikipedia about the iBook G4 that it had a soft 1.5GB limit.

[4-YearWindowsPro]

In addition to that, can you also tell us the specs of your host?

Best,
Cat_7

Currently Windows 10 x64. I'll see if I can go 11 later.
8gb RAM.
Core i7 4.00GHz

[mcayland]

In addition to that, can you also tell us the specs of your host?

Best,
Cat_7

Currently Windows 10 x64. I'll see if I can go 11 later.
8gb RAM.
Core i7 4.00GHz

That should be more than enough to run QEMU at a reasonable speed (my desktop workstation is about 8 years old), so you'll need to investigate why this issue is specific to your system. Please post some timings and work through the list of things to check from viewtopic.php?p=77562#p77562 to help eliminate these potential causes.