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Stuttering and slow downs in Gunstar Heroes

Posted: Mon Jan 08, 2024 11:01 am
by parawizard

Haven't played in a real Genesis for decades. It's normal to have stutters and slow downs in certain areas of this game?

This area seemed the worst:

s-l1200.webp
s-l1200.webp (26.11 KiB) Viewed 5481 times

I tried turning turbo onto medium for the second playthrough I think it helped.


Re: Stuttering and slow downs in Gunstar Heroes

Posted: Mon Jan 08, 2024 11:55 am
by AngelicLiver

Can 100% confirm Gunstar Heroes is choppy on real hardware, Treasure were really pushing the Mega Drive/Genesis in their titles.


Re: Stuttering and slow downs in Gunstar Heroes

Posted: Mon Jan 08, 2024 12:33 pm
by Xbytez

Agreed, slow down on the original hardware is normal with this title.


Re: Stuttering and slow downs in Gunstar Heroes

Posted: Mon Jan 08, 2024 3:02 pm
by parawizard

Had a look at YouTube and found a good examples:

https://www.youtube.com/watch?t=180s&v=gtaqQ26_PZQ
https://m.youtube.com/watch?v=deH_QOFK4Z8&t=1993s

Those dang boxes and lasers just chug


Re: Stuttering and slow downs in Gunstar Heroes

Posted: Mon Jan 08, 2024 3:25 pm
by pbsk8

Just like Jotego once said: we played on emulators for so long we forgot how games behaved on original hardware.


Re: Stuttering and slow downs in Gunstar Heroes

Posted: Mon Jan 08, 2024 3:26 pm
by parawizard

Seems like overclocking helps this game without side effects? Found a sheet showing overclocking comparability with games

https://docs.google.com/spreadsheets/u/ ... html?pli=1

10MHz

Significantly less slowdown in 2P mode during some boss fights

12MHz

No noticeable slowdown in 2P mode anymore.


Re: Stuttering and slow downs in Gunstar Heroes

Posted: Mon Jan 08, 2024 3:37 pm
by parawizard

Here's a side by side

https://m.youtube.com/watch?v=SVrElANZg2M&t=88s

Think I will play this overclocked from now on :mrgreen:


Re: Stuttering and slow downs in Gunstar Heroes

Posted: Mon Jan 08, 2024 5:07 pm
by parawizard

Wanted to understand how turbo worked in the genesis core:

https://github.com/search?q=repo%3AMiST ... pe=commits

Even after learning that 4'dX means a 4 bit decimal value of X and some other Verilog tidbits like blocking and non-blocking assignment, I am not quite sure what turbo does.

Looks like it touches VCLKCNT, FCLKCNT and also adjusts VRAM_SPEED


Re: Stuttering and slow downs in Gunstar Heroes

Posted: Mon Jan 08, 2024 5:40 pm
by parawizard

Is this block https://github.com/MiSTer-devel/Genesis ... #L155-L216 literally setting up clock sequences? I am guessing CNT is for counts. Is PAUSE_EN part of the actual logic?

Rabbit hole way too early in the morning :lol:


Re: Stuttering and slow downs in Gunstar Heroes

Posted: Mon Apr 15, 2024 7:16 pm
by Zophar
pbsk8 wrote: Mon Jan 08, 2024 3:25 pm

Just like Jotego once said: we played on emulators for so long we forgot how games behaved on original hardware.

100% this - I was streaming Dragon Warrior a couple of months ago and when I experienced slowdown in the first town when more than 5 townspeople were on screen at the same time, I had to ask in the MiSTer discord for someone who still had their real hardware working to test it - and low and behold, it slowed down in the same spot on hardware too.

Emulators spoiled me for so many years! ;)


Re: Stuttering and slow downs in Gunstar Heroes

Posted: Tue Apr 16, 2024 7:28 am
by rickdangerous

A few years ago I did an OC mod on one of my HDG precisely to solve the problem of slow downs in some games. This game is actually one of them, which pushes the MD / Genesis to the limit.