CPU idle setting and Shapeshifter/Mac emulation

[mark_k]

I normally have the CPU idle slider set all the way to the right. That minimises host CPU usage, but the emulated Amiga is still fast/responsive.

Running the ShapeShifter Mac emulator, I noticed that certain CPU-intensive Mac programs don't seem to trigger WinUAE's use-more-CPU behaviour when needed. The emulated Mac itself does boot quickly however.

Unpacking an archive with StuffIt Expander 5.5:
1. If you drag a .sit icon and drop it on the StuffIt Expander icon, the program runs and unpacks the archive very quickly.
2. However, if you run StuffIt Expander then choose the File->Expand... menu item, unpacking is really slow. CPU% indicator shows around 10% for me while that's in progress.

If I change the CPU idle slider position to the second-rightmost position, CPU% indicator constantly shows 100% and the second method above runs quickly.

[mark_k]

I've uploaded an archive (~34MB) to

https://www.media!fire.com/file/n3zthtxtlrds8zh/SS_test_for_upload.tar.7z

That contains 20MB HDF, WinUAE config, and two Mac hardfiles (to be put in shared directory).

Load config (adjust paths to suit your system), boot HDF. Run ShapeShifter, click Start. Mac OS 7.5.3 will boot.

With CPU idle slider all the way to the right, drag & drop Archive.sit icon onto the StuffIt ExpanderTM icon above it. You might find the unpacking (of file Disk9.image, its icon appears on desktop) actually happens very quickly. But then change CPU idle all the way to the left, repeat unpacking (also very quick). Finally, move CPU idle all the way to the right again and unpack the archive again. This time it should be really slow.

You may also be able to see slowness if you open Read Me (in Sys7.1 volume). Click and hold down arrow at lower right of window to scroll down. It scrolls slowly, with CPU indicator remaining at 0% for me. Same with CPU idle slider in the 2nd-rightmost position. But with slider in the 3rd-right position, scrolling is fast and CPU indicator always shows 100%.

[Toni Wilen]

Seems like something is missing: "PrepareEmul is not installed"

[mark_k]

I couldn't get PrepareEmul to work in emulation, just got a very fast reset/reboot loop. Didn't bother looking into that, instead I patched Kickstart so chip memory starts at $2000. No need for PrepareEmul then. Check your Kickstart ROM path in the config file...

But actually, you could just tick ShapeShifter support in ROM settings instead.

[Toni Wilen]

I didn't notice it was patched rom..

Can you still duplicate cpu idle issue with latest beta? It reduces idle state when DMA-like HD access happens, including uaehf.device. Which was previously detected as fully idle (If program that accessed HD was the only active task)

[mark_k]

I couldn't reproduce the slow-unpacking with 3.6.0b5, but then I went back and tried with b4 and didn't see the issue there either.

However the slow scrolling in SimpleText is still there. Open Sys7.1 icon, double-click Read Me. Hold down the down arrow at lower right. When the CPU idle slider is in the two rightmost positions scrolling is very slow and CPU% stays at 0%. CPU% is 100 with the idle slider anywhere else (and scrolling is fast).

The same issue is noticeable with the menus at the desktop. Move mouse to menu strip, hold left button and move pointer left and right. Drawing the different menus is relatively slow and CPU% stays at 0.