Zero: Exit a game, system freezes, screen is dim, can't SSH in...

Dochartaigh

Pi Zero 1.3, RetroPie 4.1.14 from the RetroPie site. Samsung EVO 16gb card, with nice 2.4 amp power supplies and cables. Amazon Basics hubs, with iBuffalo controller, wifi and wireless keyboard dongles plugged in.

As far as config file tweaks it's a pretty standard setup: disable overscan 1, hdmi drive 2, hdmi mode 4 (720P), standard Github Wiki overclock - that's it (besides consolidating save game directories, and turning on CRT-Pi shader for NES).

So I had a wonderful weekend playing with RetroPie 4.1.14. With the suggested GitHub/WiKi overclock on my Pi Zero 1.3 I was finally able to get at or super close to 60 FPS on the majority of SNES games!

...but upon further testing tonight my two systems are freezing the same exact ways: upon hitting Select + Start to exit from a game, it exits out to a dim screen (like it's been automatically dimmed/screen-saver after being inactive for so many minutes), and the system is frozen. OR, I'll just be switching from one game title in the menu to another and it freezes. I also CAN'T SSH into the Pi for the first time ever after it freezes (I've had LOTS of crashing problems before but could ALWAYS SSH in no matter what)...this is totally frozen.

I had imaged the card last night so I've tried this on 4 different SD cards now (including the original), on two different Pi Zeros to the same effect. Could it be the overclock? I just took the overclock off two SD cards (original and a copy) and am going to run them through their paces again and see if they freeze at any point (I'm currently 10 minutes in and the 1st one hasn't frozen at least...)

There's never, ever, been an error log in /dev/shm/ for me. Is there any way to turn on error logging so I can see what's making it freeze? I'm literally loosing like 5 FPS in SNES without overclocking...would hate to have to turn off the overclock and deal with slow SNES again...

CortexVacua

For me it sounds like it could be the overclock. Overclocking has no recommended value bc, every single physical cpu performs slightly different. Some can run on higher clock speeds than others. This is bc it's impossible to replicate the exact same chip twice. So the chips are tested by testing if they run at the default clock speed without any problems. How much you can turn up the clock speed differs whith each device. So you have to test on which clock speeds your devices run without crashing and stable. Once you've got that sorted out you should be fine to go, but don't forget to cool your devices (if in a case; active cooling is better than passive) to prevent permanent damage.

Tl;dr
It's about finding the right clock speed. Maybe you are lucky and one of your devices will hit the 60 fps mark with a stable clockspeed, but don't just pump it up to the max.

Dochartaigh

@CortexVacua
Huh, I never new that each processor is every-so-slightly different. I could have totally accidentally switched Pi Zero's from what I was using this weekend (have like 4 on my desk I test on).

So since I'm totally new to overclocking, what settings would you suggest - I'm definitely going to go lower so it works on ALL Pi Zero's (I'm messing with a new image to get my couple cousins who like SNES best better performance...and some games like Alien 3 run at like 40 FPS without overclock...so it definitely needs something extra). My current settings are this:

arm_freq=1000
gpu_freq=500
core_freq=500
sdram_freq=500
sdram_schmoo=0x02000020
over_voltage=2
sdram_over_voltage=2

Seems like the stock/default (non-overclocked) settings are:

arm_freq=1000
gpu_freq=300
core_freq=400
sdram_freq=450
sdram_schmoo=0x02000020
over_voltage=??? (can't find the default value)
sdram_over_voltage=??? (can't find the default value)

BUT, the GitHub doesn't make it simple..it says to keep the core_freq the same as gpu_freq...yet the default settings are different from each other... Also says that if you have issues to raise the voltage? ...which likewise doesn't make sense to me from a stability standpoint.

I would be happy if I could just get NES to work at 60 FPS with lr-quicknes WITH the CRT-Pi shader turned on (without overclock it sometimes drops to like 55 FPS, with CRT-Pi turned off it's 60...but I REALLY believe 8bit and below needs a shader to look decent).

CortexVacua

@Dochartaigh
Sorry, I read through the overclocking procedure a while ago, but never actually overclocked cause I'm on a RPi 3. So I am no expert. I can't really help. But the github guide states this like you said: "You are better to just set core_freq and gpu_freq to the same thing and don't worry about it. The individual components only get faster when they are used anyway."
I would go for it even if they weren't originally the same clockspeed. Maybe some one else has some concrete tipps tipps for you.

[removed references to youtube channel that now promotes piracy]

dankcushions

the only safe overclock is no overclock. any sort of crashing or freezes... dial it back. a working retropie system should never freeze or crash unless there is a software bug, and these are normally pretty specific and reproducible.

the reason for adding over_voltage is to INCREASE stability; higher clocks demand more power. however it also raises temps...

for shader performance i would have thought only GPU and maybe memory performance overclocks are relevant.

Dochartaigh

@dankcushions said in Zero: Exit a game, system freezes, screen is dim, can't SSH in...:

the reason for adding over_voltage is to INCREASE stability; higher clocks demand more power. however it also raises temps...

for shader performance i would have thought only GPU and maybe memory performance overclocks are relevant.

I tried some new settings last night, and ran it for a good solid 20 minutes switching from game to game like I was doing before (where I could ALWAYS get it to freeze at some point) – and it seemed to be good. Think I dropped each "recommended overclock" number by 25 (475, 475, 475), AND changed the two voltages to 3. Think temp was still around 60º which is normal while you're using it I believe. I will test it even more tonight (including writing down the FPS numbers to see how they compare to the full 500 overclock - I think SNES was still down to like 54-57 instead of 60 FPS...which would be fine as long as it doesn't crash).

CRT-Pi Shader performance I gave up on for SNES and Genesis to be honest. It's just too much on the pi Zero even with the full overclock to get to that magic 60 FPS. I'm trying to keep CRT-Pi for NES (as it helps 8-bit look better to a much greater degree than 16-bit IMO), but will have to see if I get any of the weird pausing which plagued the non-overclocked Pi Zero with lr-quicknes + CRT-Pi.