No luck overclocking Retropie with Raspberry Pi 3

rdb9879

Downloaded Retropie a couple weeks ago and installed directly from SD image onto the Raspberry Pi 3

Everything works great except N64. I couldn't find one emulator/video/rom combo that was even the slightest bit playable (games were very stuttery and ran at like quarter seed).

I tried to follow this guide: https://github.com/retropie/retropie-setup/wiki/Overclocking

For overclocking under the RetroPi 3 section. I did spring for the heatsinks (CPU and GPU), 2.5A USB power supply with thickest cable I own, and made sure there was direct air flow on the heat sinks.

When I apply those settings from the guide to /boot/config.txt, I see absolutely nothing on the screen when I power it up. I tried to scale back the CPU freq, with also no luck.

What is also interesting is that according to some, I should be able to hold the shift key down when powering up to force the system to revert back to normal-clocked mode so I can at least boot and try different settings: this did not work. I had to mount the SD card on a different system to modify the settings.

I can still get the retropie to boot normally when I revert the config.txt file.

Just wondering if anyone has any ideas. Is the guide out of date? Does there seem to be an obvious issue based on my description? I'm no linux guru so forgive me that I couldn't do more independent debugging.

RetroResolution

Hi,

I've written a couple of overclocking guides, one for the Raspberry Pi 2, and one for the Raspberry Pi 3 - the newer machine, at least the one I have, generates a lot of heat, meaning that overclocking becomes a balancing act. Hopefully the the guides on stability testing will illuminate where your machine is having a problem.

Overclocking the Raspberry Pi 3: Thermal Limits and Optimising for Single vs Multicore Performance

The above post builds on the original series of posts, which cover overclocking, and most importantly, stability testing:

Overclocking and Stability Testing the Raspberry Pi 2 – Part 1: Overclocking in Depth
Part 2a: Stability Testing the Raspberry Pi
Part 2b: MPrime – Multicore Testing
Part 3: MemTester – Single Core and Multicore Testing
Part 4: SD Card Stability Test Script

Topics Covered In Part 1

Why Overclock?
Raspberry Pi System Architecture
Overclocking, Hardware Lifespan, and Your Raspberry Pi’s Warranty
A Note On Overclocking and SD Card Stability
Raspi-Config Overclock Options
Editing Overclock Settings Within the Config.txt File
Help! What To Do If The Pi No Longer Boots After Applying Overclock Changes
Tested Overclock Values – Failures and Successes

Topics Covered In Parts 2, 3, and 4

Stability Testing the Raspberry Pi
MPrime – Multicore Testing
MemTester – Single Core and Multicore Testing
SD Card Stability Test Script

RetroResolution

Regarding N64 performance, I found this also; reducing the emulator resolution to 640 * 480 in the RunCommand menu made a huge difference.

I'm currently running my Pi 3 with a monitor, so the video modes are selected from amongst the DMT options:

DMT_4 640 x 480, 60mhz,4:3 Progressive

on a 1080p TV, I use
CEA-1 640 x 480, 60mhz, 4:3, Progressive

I leave the framebuffer value at default (320 x 200).

GPU Memory can be a factor. I currently have my system using a 128MB split, but you may wish to increase this to 256MB

I don't use the libretro core version of Mupen64 (lr-mupen64) as I've never found any games that work as well as they do on the non-RetroArch emulator.

The performance depends heavily upon the video core chosen, and the game itself. The N64 allowed the video chip to have 'microcode' written specifically per-game, basically programming the GPU directly. This makes emulation very difficult (from what I've read)

The ROM Compatibility List Google Docs spreadsheet, linked from the RetroPie wiki, is very helpful in determining if you have a chance of getting a specific title working well

Selecting the appropriate graphics core is critical. I haven't tried the new core added in the very latest release, included with RetroPie 3.8, but I have used the following:

(all running on a Raspberry Pi 3 overclocked to 1350mhz. At the time I took these readings I was using RetroPie 3.6)

Working Flawlessly, or very well:
Super Mario 64 - seems to work flawlessly on all available video cores (was obviously a test bed when the emulator was developed)

Super Mario Kart - gles video core. Uses 33 - 50% of 1 CPU Core in-game. Virtually flawless

Wave Race 64 - Glide video core- smooth, uses c. 68% of 1 CPU core

Doom 64 - Gles video core - in-game uses 25 - 30% of 1 CPU core

Playable:
Ridge Racer 64 - Glide - in-game, pretty smooth. Replay mode - stutters. Attract mode - some audio stutter. Peaks around 90% of 1 CPU core

Not working so well:
GoldenEye - Glide video core; uses 45 - 70% of 1 CPU core. Audio is 'scrappy'
PilotWings - Rice - best of the bunch, but still slow. Gles - unplayable

Riverstorm

@RetroResolution said in Yellow/Gold warning square in the top right hand corner:

Posted in the wrong thread but I had a question about your guide in the other thread, posted there.

RetroResolution

@Riverstorm No problem, I've replied on the other thread!

ProxyCell

I will throw in my own two cents here:
I had a lot of trouble with OC on the RPi3 and gave up for a while there. Now it seems to run perfectly well:

Ensure a proper electrical cord/power supply - It must be plugged in WELL too. I find this to be the biggest issue overall for people actually. If you are in doubt, just buy the official RPi power supply.
Heat is an issue but not the be-all, end-all. A cheap heatsink should do the trick.

mrbwa1

With overclocking, often the memory is the biggest limiting factor. Try scaling back memory and/orGPU overclock. Some memory chips can do 500MHZ, but many can't.

As for N64 Emulation (I have only tried on an RPi2):

As noted above: 640x480 helps tremendously
I have had best luck with the 128MB GPU memory split
In reality, the GPU isn't hardware rendering, so there is no need to go above 128MB

N64 Emulation is simply very difficult and very CPU-intensive. When games run, they look really nice, but I have yet to run 1 that doesn't have some glitch compared to my OG N64 carts. A lot of games ran okay at 640x480 with the various plugins once in the game, but the menus and sound are often a mess. The architecture is so odd, then even when the N64 was new, developers had a lot of troubles with it, leading to many different ways to implement features. In a way, it's somewhat comparable to MAME where emulators need to target specific code for specific games and/or developers due to the various implementations of games on the (compared to say the PS1 whever most development was very alike and straightforward).

dankcushions

@mrbwa1 n64 (HLE) emulation isn't CPU intensive really. look at top command when it's running. it's GPU - that's why lowering resolution helps.

it is certainly using hardware rendering, though

mrbwa1

@dankcushions said in No luck overclocking Retropie with Raspberry Pi 3:

@mrbwa1 n64 (HLE) emulation isn't CPU intensive really. look at top command when it's running. it's GPU - that's why lowering resolution helps.

it is certainly using hardware rendering, though

Looks like it's tome for me to look back at what's being used. Certainly, trying to render at 1080p is going to use a lot more GPU than 480p. And if someone doesn't like the look @ 480p, they should look at the original N64 hardware running through a flat screen! (S-video helps a lot: that or having the $$ and hardware to do the HDMI and RGB mods.)

To sum up my thoughts: N64 emulation is really hard and it's not the hardware itself that seems to be the limiting factor. The actual emulation is extremely difficult.