Poor C64 Vice performance on Epyx "Impossible Mission"

T_Scheen

Hi there, this is my very first post, so hopefully not making mistakes.
I have very recently bought a pre-built Zarcade Z8. Main purpose is to play my favourite C64 game of 35 years ago, Epyx Impossible Mission.
However, the screen performance is quite poor.
Scrolling is lagging and my character is moving slow. Barely playable.
System:
Raspberry Pi 3B+
Retropie 4.6.4
ES v 2.9.3 RP
Vice 3.4 Rev 38100

As there are so many potential settings to tweak in Vice, I'm getting desperate.

Can anybody help with a golden tip, preferably someone with the same Zarcade/Vice setup?

T_Scheen

I think I found it:
Set "Refresh Rate" from "Automatic" to "1/1" and leave CPU speed at 100%.

stoo

If your system can run VICE at full speed then 1/1 is the same as Automatic.

Pi3B+ can run VICE fullspeed, but not with any enhancements. You can't use Double size, Double scan or any Render filters (CRT Emulation or Scale2x) and maintain full speed.

Why? Well, it appears that FastSID support was removed at some point. ReSID is very heavy on the CPU, which is probably why the options I listed above are no longer viable on the Pi3, even overclocked.

The Pi4 has enough power to run fullspeed with any/all enhancements enabled.

BuZz

@stoo I will look into possibly adding an older version with the less accurate SID emulation.

stoo

@BuZz Cool, thanks. It doesn't actually bother me - I prefer the accuracy of ReSID - but it would probably be nice for users like OP to have the option.

BuZz

Looks like it's a configure option that's now disabled by default. Testing with it enabled and if all ok will rebuild binaries and update module source.

BuZz

Source is updated. If you update RetroPie-Setup script and then install vice from source the fastsid backend should be available again.

BuZz

Binaries are now also updated.

stoo

@BuZz Awesome, cheers.

T_Scheen

@BuZz said in Poor C64 Vice performance on Epyx "Impossible Mission":

Source is updated. If you update RetroPie-Setup script and then install vice from source the fastsid backend should be available again.

Cheers mate!
Took me a while to figure out how to enable wifi first on my Zarcade. And I had to buy a keyboard first of course. Today I was able to update the Vice package. Found the FastSid setting (6581).
The proof of the pudding in my favourite game: When you travel up or down with the elevator for a long time, there is no more stuttering in the elevator sound.
Thx !!