Tell me about the Raspberry Pi

[Skykid]

It's up to version 3 now, 1GB RAM with Bluetooth and WiFi installed.

I know version 2 had a VGA adaptor developed for it which is now available for sale, but it doesn't have the same RAM or wireless connectivity of the newer one.

What I'd like to know is any firsthand experiences using this thing for emulation: how it runs, speed, any issues etc. Retropie looks great these days, the interface is nice, but how does it hold up for general use and configuration?

With no VGA out on the model 3, does retropie support scanline shaders?

I'd also be really interested to hear about anyone who's got this running in an arcade machine project, because apparently there's a special power switch unit devised just for the purpose of shutting down a cab with one installed.

It does seem too good to be true at $35, I hope that's not the case. Thanks for your help!

[Nug]

I run a raspberry pi 2 currently. I have a cheap hdmi to vga adapter to run it on my monitor. Mame works well, although there are slight graphic flaws like tearing etc in some games like 3rd strike and marvel vs capcom. the only games Ive currently had issues making it unplayable are psp, but I haven't bothered to work on it in awhile.

Go in the retropie forums and get a scanline overlay. There are some good ones people have made, really makes it look better. Overall, I like it alot. It's cheap and easy to set up, and it's portable. Don't expect perfection though. It doesn't come close to a groovymame setup.

[Fudoh]

Unless you want to dive really deep into emulator configuration and adding obscure systems, I would recommand RECALBOX over RetroPie.

Most systems including PCE, MD, NES, Neo Geo and Playstation run flawlessly. SNES is a bit laggy out of the box, but can easily be adjusted to run quite nicely as well. Configuration is as easy as it gets (put Recalbox image into a SD Card, put it into your Pi, wait for the installation to finish, done). You add roms by logging into the system through a web interface (or via Samba using a network share). With Recalbox for the whole setup process you don't even need a keyboard. Very much feels like a console. RetroPie not so much.

Scanline emulation is available and looks very nice. The whole system runs at 720p. You can choose 1080p instead, but the Pi3 isn't powerful enough to run the retro shaders at 1080p.

Perfectly worth the money! If you want to use Bluetooth controllers you need a BT dongle since Recalbox doesn't yet support the Pi3's internal BT chipset.

What you need (or want):

- Pi3
- Case
- 16GB+ SD Card
- PSU 5V at 2.5A (Micro USB connector)
- BT dongle (for Bluetooth controllers)

[Guspaz]

but the Pi3 isn't powerful enough to run the retro shaders at 1080p.

This is because the Pi's GPU is one thing that has essentially remained at a standstill since the very first version.

From the Pi 1 to the Pi 3, it has 4x the RAM, and 10x the CPU performance (more if they did a 64-bit OS)... but they are still using the very same VideoCore IV as they did at the very start, with only a minor clockspeed boost (1.2x clockspeed for graphics engine, 1.6x for video decoder).

This is one of the components that is holding back the Pi the most at this point, since the fact that all the other aspects of the Pi have advanced so much makes the GPU much slower than it used to be in relation.

Unfortunately, this is unlikely to change. The Pi is essentially a Broadcom product, and Broadcom has not released a new GPU in 5+ years, that being the VC4.

[Xyga]

For crt effects there's also the .PNG overlays, I think lettuce mentioned trying that on the Pi, dunno if he did.

[Skykid]

Thanks guys, very useful. I didn't actually know Recalbox existed until now, I'd been scanning all the Retropie stuff. Streamlined is definitely my preference as long as it's configurable enough, so Recalbox sounds good to me.

Some more Qs:

SNES is a bit laggy out of the box, but can easily be adjusted to run quite nicely as well.

SNES is my most wanted on my most wanted list. Laggy doesn't sound good.

I've had a look at some YT examples and they seem ok. Even Starfox seemed to run pretty well. Would you mind elaborating a bit on the issues and required adjustments? And any other systems that suffer from performance issues.

(Really no idea why SFC is such a pain to emulate after all these years!)

Most systems including PCE, MD, NES, Neo Geo and Playstation run flawlessly.

PlayStation seems very nice, as does N64, from what I've seen just now. How about PC-CD stuff and things like Daphne?

I have a cheap hdmi to vga adapter to run it on my monitor.

Yep, I've been eyeing these up. Has anyone stuck an SLG or XRGB series in between the platform and the monitor for scanline rendering yet? Your findings would be cool (I'm sure Fudoh's done this!).

For crt effects there's also the .PNG overlays, I think lettuce mentioned trying that on the Pi, dunno if he did.

PNG overlays have always been good enough. I'm assuming Recalbox (like Retropie) is also built on Libretro's Retroarch core? Retroarch supports various PNG overlays that can be downloaded within the GUI, does Recalbox etc also support this?

One last thing: for use in an arcade machine, has anyone tried any of the various power off switch adaptors for the Pi? I believe they were designed to let you shut down the machine and the Pi without losing any saved info or configurations etc.


Appreciate the info!

[Fudoh]

SNES is my most wanted on my most wanted list. Laggy doesn't sound good. I've had a look at some YT examples and they seem ok. Even Starfox seemed to run pretty well. Would you mind elaborating a bit on the issues and required adjustments? And
any other systems that suffer from performance issues.

different cores I guess. PCE and many other systems run on the Mednafen core ported to Libretro, while SNES is based on SNES9X. With the default options some of the SNES game felt (and measured) a bit to laggy. But there are options in Retroarch (e.g. "Frame Delay") which can counter this. After adjusting these SNES felt ok (while still a frame slower than PCE for example). Switching the core (PocketSNES instead of SNES9x) felt better, but the emulation itself (especially the sound) is worse.

Using the manual lag test on the 240p test suite PCE and other systems come out at 1-2 frames above the display's native lag, while SNES adds a frame to that (or three without adjusting the options).

PlayStation seems very nice, as does N64, from what I've seen just now.

For PSX almost everything plays perfectly, while for N64 it's very much up to the game. Some games play good, others don't. I really don't care for N64, so I haven't tried much.

How about PC-CD stuff and things like Daphne?

PCE CD runs perfectly.

I'm assuming Recalbox (like Retropie) is also built on Libretro's Retroarch core? Retroarch supports various PNG overlays that can be downloaded within the GUI, does Recalbox etc also support this?

You get the full Retroarch/Libretro options once the emu is running.

One last thing: for use in an arcade machine, has anyone tried any of the various power off switch adaptors for the Pi? I believe they were designed to let you shut down the machine and the Pi without losing any saved info or configurations etc.

Recalbox runs on a write protected environment, so there's no chance you're losing anything. You can power down the Pi through the Recalbox GUI. The Pi restarts when the power is cut and restored, which is certainly handy when running it on the 5V rail of your arcade PSU.

Yep, I've been eyeing these up. Has anyone stuck an SLG or XRGB series in between the platform and the monitor for scanline rendering yet? Your findings would be cool (I'm sure Fudoh's done this!).

as long as you run a 31khz output (or higher) from the Pi, just use the internal shaders and scanline options. Why would you want to use external ones instead ? If you want to use a SLG for performance reasons, that should be fine. Feeding a XRGB with a 240p signal from the Pi seems so much more complicated, especially when you want a 480p signal eventually anyway.

[Skykid]

Yeah I just figured an SLG would appear more authentic than an overlay, but I'm happy to see how shaders etc look first.

Re: SFC, is CATSFC available as a core? Recently the retroarch cores were split and made available individually for the recent PS Vita Henkaku hack. I'm using CATSFC and the performance is far superior to SNES9x, which has ways been kind of ropey in places.

Speed seems 100% and the sound rarely stutters.


Thanks for all the info here chaps!

EDIT: sorry I may be wrong about CATSFC as part of Libretro, I'm not sure now. It might be independent. Either way it seems more solid than SNES9x, I wonder if it can be added on Recalbox?

[Fudoh]

I think it's included, but it didn't feel as good as SNES9x in terms of sound and music.

[Einzelherz]

Possibly stupid question:

Recalbox sounds lovely, but I'm curious. Would it be possible to set up two of them (one on HDTV@720p, one on SDTVs@480i/240p) and have them share networked save files? I find myself varying in mood whether I want to play on either screen (don't care about blank lines on an HDTV) and it would be neat to not have to move the system back and forth.

[Fudoh]

You could move the SD card though

Since both systems give you network shares, I guess you could synchronize them running a 3rd party software on a PC or MAC.

[Einzelherz]

I'd thought of moving the SD card but wanted to be even lazier

If they're both networked it should be as simple as pointing the emulators to a network save file path, right?

You mentioned that it could only output 720p earlier, Fudoh. Did you mean that that was it's ceiling, but not its floor?

[Fudoh]

If they're both networked it should be as simple as pointing the emulators to a network save file path, right?

probably, but I don't know how network shares under linux work or how to configure it. Seems possible though.

You mentioned that it could only output 720p earlier, Fudoh. Did you mean that that was it's ceiling, but not its floor?

as far as I know you can even run 240p, but I guess the Recalbox GUI isn't built for that. 480p is no problem.

[Skykid]

I think it's included, but it didn't feel as good as SNES9x in terms of sound and music.

It's really much better on the Vita, but that could be hardware specific.

Regarding Recalbox, this is probably an obvious one, but VSYNC is available right? No screen tearing or anything like that?

- 16GB+ SD Card

SD or Micro SD?

[Fudoh]

It's really much better on the Vita, but that could be hardware specific.

yeah, but I'm pretty sure that the Vita is much more powerful than a Pi.

Regarding Recalbox, this is probably an obvious one, but VSYNC is available right? No screen tearing or anything like that?

of course.

Micro SD.

[Skykid]

It's really much better on the Vita, but that could be hardware specific.

yeah, but I'm pretty sure that the Vita is much more powerful than a Pi.

Yeah, for sure (but SNES 9X runs appallingly on Vita - the sound is a mess).

I found a Pi 3 for sale here for 200 Yuan, which is cheaper than UK retail price by a healthy margin - guess we know where they're manufactured then...

[Guspaz]

I've used the power switch functionality of the ControlBlock, which is from the guy who makes RetroPie. ControlBlock has inputs for arcade controls or NES/SNES controllers, but he also makes a power-only version called PowerBlock that's smaller/cheaper.

Basically, you power the rPi through the PowerBlock/ControlBlock's USB input instead of the Pi's power input, and you wire up a power button. When you toggle the power button on, it supplies power to the Pi, booting it. When you toggle the power button off, it initiates a safe shutdown of the Pi, and when the Pi is finished shutting down, it cuts power to the Pi. This ensures that you don't suffer from any file system corruption, since *any* emulation solution must have a writable file system (even Recalbox) if they want to support saving your game. It also features a power LED option, which is off when it's off, pulsing when it's booting/shutting down, and on when it's on.

If you're planning to put a Pi into an arcade cabinet of some kind, then it's a pretty good option. In my case, I wired it up to the power switch and LED of an NES, which worked fine, although I haven't figured out how to get the reset button working (the NES reset switch is wired strangely).

[Guspaz]

yeah, but I'm pretty sure that the Vita is much more powerful than a Pi.

The opposite is true:

RPi 3:
1GB RAM
1.2 GHz quad-core Cortex-A53

PS Vita:
512MB RAM
333* MHz quad-core Cortex-A9

The A53 is slightly faster clock-for-clock than the A9 (it's the low-power model but is two generations newer than A9), so the Raspberry Pi is massively more powerful than the PS Vita. The PS Vita likely has a big edge in GPU performance, but CPU performance is much more important for emulation.

*: The Vita runs at 333 MHz by default, but can be boosted to 444 MHz when wifi is disabled.

I found a Pi 3 for sale here for 200 Yuan, which is cheaper than UK retail price by a healthy margin - guess we know where they're manufactured then...

The primary two manufacturers of the rPi are both in the UK, however the pi foundation has licensed Egoman in China to manufacture the Pi for sale only in China and Taiwan. These units are illegal to import to the EU or USA, as they are not FCC/CE certified, and so have a red PCB to differentiate them from models that are legal to sell in the rest of the world.

[Skykid]

Great info, thanks. I've been thinking about hooking it up to an arcade project, yes, will the ControlBlock work with Recalbox the same it works with Retropie, or is it Retropie specific?

The primary two manufacturers of the rPi are both in the UK, however the pi foundation has licensed Egoman in China to manufacture the Pi for sale only in China and Taiwan. These units are illegal to import to the EU or USA, as they are not FCC/CE certified, and so have a red PCB to differentiate them from models that are legal to sell in the rest of the world.

Well this appears to be the UK model:

https://world.taobao.com/item/527684185 ... rGA#detail

Interesting info on the domestic model, I'd be interested to see how much they go for, but I couldn't find any red PCB boards when searching.

[Guspaz]

That photo has the Element14 branding in it, those ones are made in the UK. Well, also, the PCB In the photos on there literally say "Made in the UK" on them.

200 yuan is a sale price, taobao's regular price is 243 yuan, which is actually slightly higher than the USD MSRP of the pi. So if you're looking to pick one up, it looks like you can save a bit of money while the sale lasts.

[Skykid]

I found another for 195. Getting cheaper. But I can't find that red PCB.

195 + 6 Yuan shipping is so cheap I'm tempted to buy two in the event a future project calls for another. If the UK Pound hadn't been crippled by Brexit that would be about £20 shipped.

Oh, and let me know about that ControlBlock! If it works with Recalbox I'll almost certainly get one.

I'm just wondering if the coin mech can be wired as a hotkey at the moment, that would be neat (and mostly impractical).

[Mrhide]

this might be usefull?

http://choccyhobnob.com/articles/benchm ... pberry-pi/

[Skykid]

this might be usefull?

http://choccyhobnob.com/articles/benchm ... pberry-pi/

This is very useful, thanks for that! Actually I'm disappointed to hear that MAME has trouble running at all... that's rather disappointing. I thought if the Pi can run PSX, it should be able to breeze MAME fairly well, or at least up to a point. Can it handle Ketsui, Espgaluda etc?

Regarding that chart, forgive me - what do the percentages represent in performance terms? I'm not sure what I'm looking at when a game has a performance test of 254% for example.

[Fudoh]

Regarding that chart, forgive me - what do the percentages represent in performance terms? I'm not sure what I'm looking at when a game has a performance test of 254% for example.

I guess he's running the games without throttling the framerate and this is the speed they're running at utilizing all the available CPU power. What's stupid though is that he's running the tests with a disabled display, so as he's writing in the bold paragraph further down, 150% unthrottled speed comes out at about 100% real speed with activated display and anything below 150% in to top chart would result in dropped frames whily playing.

[Guspaz]

Did he run the benchmarks with multithreading enabled? Because if he didn't, the benchmarks are essentially invalid, and it doesn't look like he did.

[Mrhide]

He's (it ain't me! it's a link I saw at mameworld this morning) saying this is the scripts he runs for the benchmarks:

Code: Select all

#!/bin/bash
rm "$2"
while read -r romlist || [[ -n "$romlist" ]]; do
declare -a array=( $romlist )
rom="${array[0]}"
echo "Starting: $rom"
./mame -listfull $rom >> "$2"
./mame -bench 90 $rom >> "$2"
done < "$1"

and if I read this properly, that is probably what "mame benchmark" means:

from http://www.ischo.com/mamebench/

One very crucial thing to note about these results is that they were run with a custom version of MAME that has no video/sound output. This benchmark only tests the emulation performance of MAME, not the performance of the video and sound rendering. Therefore these results represent the ideal performance assuming that rendering the graphics and sound would take zero time. For most games that achieved 100% performance in this benchmark, it is expected that the overhead of video and audio for a system with proper hardware video/sound support (easier said than done in Linux!) would be negligeable. However, the benchmark program I wrote has the ability to "estimate" the video and sound overhead by busy-waiting for a configurable period each frame (as picoseconds per byte of video that would be rendered), but I haven't yet run the calculations to determine what that configurable period should be, or actually run the benchmarks in that mode.

So once again, these benchmarks are only of emulation performance, not the actual frames per second that you'd see on your screen.

[Guspaz]

Right, but he's using the benchmark to compare the rPi 1 (a single-core processor) to the 2 and 3 (quad-core processors), and he's not using multithreading, meaning the emulation is running slower on the rPi 2 and 3 than it should be. It does not accurately reflect the performance of the platform. For that matter, it's not a useful measurement either, since you can't play games with no audio or video, so you're left with the strange situation where he has to say something like "you probably need 150% in most cases to avoid frame drops", which is silly. Enable audio and video, pick a common resolution like 1080p, and then report the average and minimum framerates.

[Harrumph]

Any opinion on Recalbox vs Lakka? As far as I can tell they both use the same LibRetro cores, but is Recalbox more optimized for R-Pi out of the box?

[Guspaz]

I've only ever used RetroPie, and not a particularly recent version. Some googling around seems to indicate that Recalbox is meant to be a more out-of-the-box experience, while RetroPie is more difficult to set up but more customizable, and Lakka is a relative of one of the two and is meant to run on a more broad set of hardware.

Basically all three seem to just be distributions that package RetroArch. RetroPie and Recalbox use EmulationStation (or a fork thereof) as their front-end, while Lakka uses its own.

I've no direct experience with the current situation for this, but it seems like a first-time user with limited experience should probably start with Recalbox, and there's nothing stopping you from just trying a different one later.

[Skykid]

I checked out Odroid XU4 and it seems a lot more powerful than the Pi for emulation. It's running graphically intense games without much of a problem. Unfortunately the community is way smaller and support equally so, meaning beginners like me probably shouldn't get into that yet.

I think if Odroid picks up interest in future it's got a lot of potential as an all-in-one emulation device.