Nestopia UE Refresh Rate Problem?

RetroArch Linux devices
#1

Hi all,

First things first, congrats on a mind-blowing 1.2.x release! I’m amazed at how far the project has come along since the Ssnes days!

Alright, I am running RetroArch (compiled from source) on a Manjaro x64. Hardware-wise a Shuttle DS57U - a feisty little fanless Broadwell Celeron 3205U. That’s 2 [email protected] with Intel Gen8 HD Graphics. I run almost everything full speed with the most common shaders (CRT Hyllian, CRT-Easymode-Halation from that NeoGaf thread) except Mednafen PSX - which I assume is because of the lack of horsepower - and, to my surprise, Nestopia UE.

For some reason, Nestopia cannot seem to run at more than 30hz. Sound and framerate is choppy as if the PC couldn’t handle it (similar to Mednafen PSX). I tried enabling/disabling shaders, VSync… The only thing that “works” is enabling threaded video. But then, it’s not as “smooth” as the other cores.

I seem to remember that Nestopia requirements are higher than other NES cores and I know that a Celeron is not exactly a powerhouse but surely, it should be enough?

Anyone experiencing the same thing or any idea what could be happening?

#2

Hmm. yeah, that’s weird. It shouldn’t be that heavy-duty. Does it help if you disable the audio and/or mess with audio latency?

#3

Thanks for the reply hunterk.

Unfortunately, setting the audio driver to null and/or changing audio latency has no effect either. I have tried enabling/disabling XFCE compositor as that has caused trouble in the past but to no avail. Started from scratch from a virgin retroarch.cfg file too…

I thought some Broadwell related settings may be to blame, namely: https://wiki.archlinux.org/index.php/Intel_graphics#Tear-free_video https://bugzilla.kernel.org/show_bug.cgi?id=95741

But playing with these haven’t changed a thing either. This is all very baffling… By the way, what is the recommended CPU for Mednafen PSX? I only get 9.4 fps which seems awfully low.

EDIT: I have now tried two kernels (3.18 and 4.1), switching back to the UXA acceleration instead of SNA… Still nothing. Log looks normal. Audio buffer is only 13% full (52% on Snes9x and that runs full speed).

#4

One more thing regarding Nestopia: your CPU could be aggressively clocking down when it thinks the task isn’t heavy enough, which could be causing the issue. You can try opening a terminal and giving it a garbage task, like “yes > /dev/null” or “openssl speed” at the same time and see if that helps.

This can be an issue on really light emulators because it finishes emulating the frame in 1 ms and then sits idle for 15 ms, which some CPU throttling software sees as an indication that it’s time to clock-down.

#5

Stilll no luck =(

I slapped a Windows 10 on the same PC and turns out both Nestopia and Mednafen PSX run fullspeed. I’m going to blindly put the blame on the state of Broadwell graphics drivers or some power management issue. I think I’ll dual boot until the issue is resolved. Still, funny that it should only impact those 2 cores…

Thanks for your time and help!