CPU governor and overclock threshold

Rion

@BuZz said in CPU governor and overclock threshold:

Thanks - there is a bug on the RPI - which may be due to some behaviour change in the kernel or I just missed it before when testing.

it saves the "previous" values of the CPU governors in an array, but it does this in the same loop as it sets them. On the RPI if setting cpu0 to performance, cpu1 will also be set to performance (no per core setting supported). So it gets the value performance back, and when restoring the values, it will end up leaving them in performance (or whatever was chosen).

This code works fine on my PC - as each core can be set individually. I will save the values first before setting, which should resolve it.

So in other words a fix is needed for the kernel or the script?

BuZz

A fix in the runcommand.sh so it will work correctly on machines that have multiple cores but a single governor for all.

Fixed in https://github.com/RetroPie/RetroPie-Setup/commit/0951d9d3581588822a5b66e2d990f8c7b5a17341

updating retropie-setup script should sort it.

Rion

@BuZz That was fast thank you!

Riverstorm

@BuZz said in CPU governor and overclock threshold:

A fix in the runcommand.sh so it will work correctly on machines that have multiple cores but a single governor for all.

Fixed in https://github.com/RetroPie/RetroPie-Setup/commit/0951d9d3581588822a5b66e2d990f8c7b5a17341

updating retropie-setup script should sort it.

Great, thanks Buzz for the quick fix! Ok, dumb question so are you joolswills? I always check the commits daily. I guess I never made the connection. I saw a post on another thread by you that was WAY above my comprehension on caching and writing to improve performance.

If I can ask one question, does install Experimental packages or installs in general tax the Pi? What I mean is when I would install Daphne overclocked to 1350 I crashed every time but at 1300 it installed just fine every time. The overclock settings above are what is stable with a decent 2A (I think 5.3v) power supply for my particular Pi 3's.

BuZz

I am.

Compiling some experimental packages will make it work yes - as it will use more than one core for compiling. So if your machine crashes, it is likely you do not really have a stable overclock (many emulators are single core, so it might seem to be stable with them, but it may not actually be a stable overclock when more than one core is in use).

Riverstorm

@BuZz said in CPU governor and overclock threshold:

I am.

Compiling some experimental packages will make it work yes - as it will use more than one core for compiling. So if your machine crashes, it is likely you do not really have a stable overclock (many emulators are single core, so it might seem to be stable with them, but it may not actually be a stable overclock when more than one core is in use).

Very cool, you do some very impressive work and thank you so much for such an awesome program! :)

Ok, that makes sense it would work at higher overclocks for gaming but failed compiling Daphne so I kept lowering until Daphne successfully compiled and left it there. I figure a little overclock is better than none. I think the success of the Pi speaks for itself and the gaming will just get better with each generation of Pi. I think its here to stay.

BuZz

Welcome (team effort of course) :)

Riverstorm

@BuZz said in CPU governor and overclock threshold:

Welcome (team effort of course) :)

Perfect Buzz, it worked flawlessly. I really like this solution as it's a win-win really. People can overclock and then use the performance governor to take full advantage of the overclock when you need it most while running a game and downclock when sitting at the menu. It's brilliant really.

RetroPie is the only reason I bought a Pi (several actually). It's definitely in my top 10 coolest things of all time, RetroPie that is, the Pi alone just doesn't cut it! ;) RetroPie adds the Midas touch to the Pi. I guess you can't put a price on nostalgia! :)

dankcushions

@Riverstorm said in CPU governor and overclock threshold:

I believe it supposed to set the threshold to 60% utilization before overclocking where I think the default is 95%? I thought lowering it might make it a bit snappier. I was running Gauntlet Legends on N64 and through a Putty session I saw it kept downclocking to 600 several times just booting up and sitting at the intro screen.

i imagine it's doing this because N64 emulation doesn't really push the CPU, but rather the GPU. it just doesn't need the power.

however, the GPU down-clocks also. i wonder if they do it in tandem? might be worth experimenting with. use the command:
vcgencmd measure_clock
to measure GPU 3d clock speed in real-time

Riverstorm

@dankcushions said in CPU governor and overclock threshold:

@Riverstorm said in CPU governor and overclock threshold:

I believe it supposed to set the threshold to 60% utilization before overclocking where I think the default is 95%? I thought lowering it might make it a bit snappier. I was running Gauntlet Legends on N64 and through a Putty session I saw it kept downclocking to 600 several times just booting up and sitting at the intro screen.

might be worth experimenting with. use the command:
vcgencmd measure_clock
to measure GPU 3d clock speed in real-time

Thanks Dank, I tried the command but I must need to install a package? It gave me an error when I ran it.

That's ok as my technical ability is pretty low unless the output is pretty self-explanatory but even then I wouldn't know how to implement any changes beyond tweaking.

I think Buzz hit the nail on the head with what I was shooting for, unless there is more performance to be gained. ;) I suppose it's diminishing returns on performance vs. tweaking on what the Pi is capable of but Twitch's thread gave me hope that there are some good N64 games that are quite playable on the Pi 3.