Emulation very slow in 2.5.21/22dev

[Mousey]

Sorry to have to create another thread, following the one about the Launcher taking a lot longer to load, but a far more serious problem has come to my attention when trying to actually play some games!

Without changing any configuration files or settings whatsoever, my games run about 4 times slower in 2.51.21/22dev. At first I thought it was something I had accidentally changed, so spent a good while going over settings.

Finally, out of desperation I reinstalled 2.5.20dev over the top and boom - everything ran fast and smooth as before. Just to triple check, I reinstalled 2.5.21 and 2.5.22, and sure enough - very slow again. Reinstalled 2.5.20dev, all lovely. This is under Windows 7 64 bit.

Sorry to post these kinds of threads, as I really appreciate all the hard work that goes into FS-UAE. The slow launching I could put up with, but all my games are literally unplayable in 21/22dev, so I'll have to go back to 20dev for now.

[FrodeSolheim]

I haven't done any investigation into this "issue" (I call it "issue" because it isn't yet known if it is a bug, or just general higher host requirements due to increased accuracy).

I haven't made any changes between .20dev and .21dev which should explain any significant slowdowns. But, I have between those two versions updated the emulation core from WinUAE 2900b19 to 2900b25.

So my guess is that a change in one of the WinUAE betas (possibly an accuracy improvement) has effectively raised the minimum requirements...

I guess some kind of benchmarking would be useful to see if the change is dramatic (I don't really "notice" anything myself on my relatively powerful PC). One way you or anyone else can help to track down the change is to try the WinUAE betas, if possible, between 2900b19 and 2900b25 (inclusive) to see if any of the beta version suddenly runs slower.

(EDIT: or SnakeCoils can try compiling different git commits between FS-UAE 2.5.20dev and 2.5.21dev to see what WinUAE merge commit, if any, introduces the change).

[SnakeCoils]

Originally Posted by FrodeSolheim

SnakeCoils can try compiling different git commits between FS-UAE 2.5.20dev and 2.5.21dev to see what WinUAE merge commit, if any, introduces the change).

I'm going to do it, I will follow the WinUAE core changes but I suspect the issue comes out with adoption of core from WinUAEb25... I will check if there are some performance issues between b24 and b25.

[FrodeSolheim]

Originally Posted by SnakeCoils

I'm going to do it, I will follow the WinUAE core changes but I suspect the issue comes out with adoption of core from WinUAEb25... I will check if there are some performance issues between b24 and b25.

I agree that the following item from the b25 changelog sounds like something which could affect performance:

More accurate 68000 prefetch mode instruction cycle usage, added non-static cycle counting (mul, div etc..)

b22 also has a change which sounds relevant:

68000 CE mode IPL line sampling timing update. Do it during any memory access, not just prefetches

[tlosm]

Frode in my machine everything run good like usual.
i had been tested the Startruck demo and run perfect in full multitasking during gitting and browsing here

ah ... is better use fs uae with Amiga 4000 with ppc because Amiga1200 with blizzardppc is slow because look like lack of some dma on WinUae Too

[SnakeCoils]

Originally Posted by FrodeSolheim

b22 also has a change which sounds relevant:

68000 CE mode IPL line sampling timing update. Do it during any memory access, not just prefetches

Just finished the build of commit 6127288 (2900b22), it works at full speed

Edit: commit 720edf8 (2900b24) also runs at full speed

Edit2: commit 324d659 (2900b25) is to blame, the slowdown start here...

[Mousey]

Originally Posted by FrodeSolheim

So my guess is that a change in one of the WinUAE betas (possibly an accuracy improvement) has effectively raised the minimum requirements...

Thanks for the reply.

I could understand that if I was running on a low-spec machine, but I am running on a very high end machine, capable of playing the latest games (e.g. Alien Isolation) at the very highest settings without any slowdown, so I can't see it being my machine.

Also, in version 2.51.20dev, I can emulate a 4000 running at a blistering speed, but yet in version 2.51.21dev I can't even emulate a 500 at more than 25% speed! The base requirements (for WinUAE) couldn't have jumped so extremely between versions!

I've read some of the other replies here, and any help is much appreciated, but I will try the various versions of WinUAE tomorrow to see if I can pinpoint which version the slowdown begins.

[Retro-Nerd]

Also, in version 2.51.20dev, I can emulate a 4000 running at a blistering speed, but yet in version 2.51.21dev I can't even emulate a 500 at more than 25% speed!

That's strange. For me it was the other way around. I had speed problems with higher machines up to 2.51.20dev, and with 21dev its runs again at full speed with A3000, 4000 etc.

[Mousey]

The other problem I was having (slow launch) has been fixed in version 2.51.22dev2, which has also resulted in the emulation slowdown being fixed too! See:

http://eab.abime.net/showthread.php?p=992016

I will leave it to those more knowledgeable to postulate why, but I am delighted - thank you so much for your fast work FrodeSolheim!

[kkgarbod]

hmm seems 22dev2 (fs-uae-suite_2.5.22dev2+portable_windows.zip) one is horribly slow here

not sure why. Did a clean install and still no go

Attached logs (I'm still stuck on XP)

[FrodeSolheim]

Originally Posted by kkgarbod

hmm seems 22dev2 (fs-uae-suite_2.5.22dev2+portable_windows.zip) one is horribly slow here

One important question: is .21dev also slow? Can you also provide screenshots with the Ctrl+F10 performance graphs displayed?

Ideally, one screenshot with the last "fast version" and one with the first "slow version" (with the same game/screen).