MT32 emulation now slows down most games (on Windows 7)

CaptainJei · Post by **CaptainJei** » Sat Oct 20, 2012 8:15 am

When I play Sierra and Lucasarts games with MT-32 emulation selected, the games now play at a usually unbearably slow speed with stuttered sound. I'm using the latest daily snapshot on a Windows 7 machine. Is anyone else having this problem? The last time I played games in ScummVM regularly was back in December, and there was no such slow-down. Also, I've tried playing several of the games on my MUNT-equipped version of DOSBox, and all the games run at acceptable speeds.

envisaged0ne · Post by **envisaged0ne** » Sat Oct 20, 2012 5:05 pm

That's weird. I just downloaded the latest daily build. I ran KQ4, KQ5, KQ6 & Monkey Island. All using the MT32 Emulator. They all ran at normal speeds. I'm using Win7 32 bit.

CaptainJei · Post by **CaptainJei** » Sat Oct 20, 2012 8:41 pm

I'm using the Win-32bit version of ScummVM as well, but my Windows 7 is 64-bit. I don't rightly understand why it's causing problems now. Whenever I start a game (in full screen mode) the screen turns white, and the Windows 'wait' cursor appears for a bit, and then the game proceeds, but a white border is left on the right and bottom.

OmerMor · Post by **OmerMor** » Sat Oct 20, 2012 9:26 pm

Maybe you should try an older build, to rule out it's a machine-specific regression.

CaptainJei · Post by **CaptainJei** » Sun Oct 21, 2012 2:23 am

That's a good idea. I tried using 1.5.0 again, and I'm having the same problem. I don't know where to get an older build. I believe 1.4.x worked just fine.

But I've been told that MUNT was updated at some point recently, and that it may be more processor-intensive, so I wonder if that might be what's going on. I have noticed that the music DOES sound a lot more like a real MT-32.

MusicallyInspired · Post by **MusicallyInspired** » Sun Oct 21, 2012 12:05 pm

What speed is your processor(s)?

Post by **eriktorbjorn** » Sun Oct 21, 2012 12:14 pm

CaptainJei wrote:I don't know where to get an older build.

Old versions - including some really old ones - are archived in the files section of the ScummVM SourceForge page.

CaptainJei · Post by **CaptainJei** » Sun Oct 21, 2012 1:10 pm

My processor is a 1.60 GHz AMD Athlon TF-20.

MusicallyInspired · Post by **MusicallyInspired** » Mon Oct 22, 2012 3:01 am

That's fairly slow for a processor these days. I bet that's your bottleneck.

Collector · Post by **Collector** » Mon Oct 22, 2012 6:55 am

I suspect that MI is right. I have an old 1.6 GHz Dual Opteron machine with XP and it can barely handle a lot of more modern higher demand stuff like media in comparison with my other, newer machines. The Munt emulation does take some CPU muscle, This is not that noticeable on newer machines, but 1.6 is half of what many modern CPUs are.

The Munt developers are concentrating more of their efforts on accuracy than optimization.

CaptainJei · Post by **CaptainJei** » Mon Oct 22, 2012 6:47 pm

I think you're probably right about it being a processor issue. But it's puzzling to me that I'm getting absolutely no slowdown running the same games through DOSBox with the new MUNT. I figured that DOSBox would be more processor intensive than ScummVM, but I could be wrong.

Collector · Post by **Collector** » Mon Oct 22, 2012 9:49 pm

Well you might try an older version of Munt with DOSBox to see if you get the slow down in DOSBox. The built-in Munt in ScummVM, while newer, is now older than than what you can find on the Git server. Perhaps there have been a few optimizations since Munt was last incorporated into ScummVM.

CaptainJei · Post by **CaptainJei** » Wed Oct 24, 2012 7:40 am

Okay, this is strange... I reinstalled ScummVM 1.4.0, and once again the games ran at full speed (with admittedly less Rolandy music). Then I downloaded the latest snapshot and installed that, and now the games don't play nearly as slow with MT-32 emulation as they did before. There's still a slow-down during certain graphical effects (e.g. fading, pixel-at-a-time screen changes), but it's usually not game crippling anymore.

I'm not going to complain. Thanks for everyone's help!

tsoliman · Post by **tsoliman** » Wed Oct 24, 2012 10:07 pm

Why not look at the CPU usage graphs while the game is running to determine if the CPU is being pegged? I noticed the stuttering when CPU usage was 100% on one of the cores.

Collector · Post by **Collector** » Wed Oct 24, 2012 11:15 pm

Perhaps some background process eating up CPU cycles?