PPSSPP - Samsung Galaxy S6 Edge+ progressive Slowness

[Bananaclawz]

Hi all,

This one might sound weird, but I notice when I start up a game it runs flawlessly (Daxter, Tekken: Dark Resurrection, Ridge Racer, Lumines II..)

But then, 5 minutes later something happens and the game suddenly lowers it's frames by 1/4th (60, becomes 45-47 or 30, becomes 23 or 22). To resolve this i'd have to restart app before it happens again. It's not a large crowd or anything. I can play Ridge Racer and it's at 60 > Pause Game to troubleshoot ticket at work > come back and Frames are dropped to 45-47..

I am on Samsung Galaxy S6 Edge+ with the Multithreading enabled. It's like...Multithreading helps significantly...but then the Emulator forgets or does not stay connected to cores for long?

My Specs are:

PPSSPP Version: 1.2.2 Gold
Bluetooth Autoconnect + PS4 Gamepad
System chip: Exynos 7 Octa 7420
Processor: Octa-core, 2100 MHz, ARM Cortex-A57 and ARM Cortex-A53, 64-bit
Graphics processor: ARM Mali-T760 MP8
System memory: 4096 MB RAM
Built-in storage: 32 GB

[LunaMoo]

Most likely this is your case.:] Low profile devices without active cooling aren't really soo great at keeping high performance at long time and have to throttle down which is normal and wanted behaviour. Multithreading likely makes things worse since in addition to any potential speedup you might get, you also get potentially much higher load on your cpu.

Vulkan backend might probably help you, but it's only supported on pc's for now.

[Bananaclawz]

: (

Thanks for your insight. It's weird, since the phone doesn't feel that hot..

Will Vulkan make games run better on mobile devices?

[el_rika]

Install a temperature monitor (CPU Temp) and a frequency monitor (Cool Tool) and observe the connection between performance drop, temperature and Cpu frequency. If the device gets to a certain temperature where the CPU automatically lowers its frequency, then that's the issue.

You can then do a few tricks.
One would be to undervolt the CPU and it'll be a little cooler (i recommend it anyway).
Second would be to limit the CPU frequency to about 30% under the maximum and it'll never reach that high temperature (Use a Performance Governor to keep the CPU at the desired frequency non stop as you play). Third (best option) look for a custom kernel that allows you to choose the thermal throttling value and your device will fly

[TkSilver]

Vulkan can help performance, but probably not cooling, throttling, governor, or other specific mobile device issues not purely related to needing more performance headroom.

So will it speed up devices like the Shield tv with excellent cooling.... well that is the general promise of vulkan.

Will it make snapdragon 810 heat issues vanish.... odds are no, not unless it improves performance soo much that the cpu and gpu load are cut in half or so. Odds are it will probably not do that for quite a while if ever.

[brujo55]

disable dvfs https://www.youtube.com/watch?v=ZHUQ0EQepR0

install an custom kernel and enable turbo boost mode (this allow to use big cores A57 instead of little A53) masive speed up.

playing zelda twilight princess in dolphin emulator at 18 fps+

[Bananaclawz]

Hmm..

I was afraid to Root due to that KNOX Counter Triggering issue (Voiding Warranty).

Do you know if there's a way to add Custom Rom without wiping out the Internal Hard Drive?

Also, what might be Turbo Boost Mode?

Your help, is much appreciated

[brujo55]

(04-13-2016 03:12 PM)Bananaclawz Wrote:  Hmm..

I was afraid to Root due to that KNOX Counter Triggering issue (Voiding Warranty).

Do you know if there's a way to add Custom Rom without wiping out the Internal Hard Drive?

Also, what might be Turbo Boost Mode?

Your help, is much appreciated

http://forum.xda-developers.com/galaxy-s...l-t3100395

[Bananaclawz]

Hmm, I have rooted, but presently have no way to determine how to max out all 8 cores.

When playing I have CPU-Z running and it shows 25% of CPU being used. Metal Gear Peace Walker always seems to slow down During the beginning training scene, and horrendously slow when he ends up in the beach terrain (First Mission).

Any ideas how to max out Samsung s6 Edge Plus? I confirmed SetCPU is set to "Performance" but have no idea how to utilize all 8 cores, or even go to 2.1 Ghz

---

See attachment of Peace Walker

Because dfvs has no permissions, and CPU/GPU is not bottlenecked (I think) yet the CPU shows 19% used (On Upper Left). The GPU Memory isn't even red. All settings I've tried, with minimal and maximum in the emulator reduce the game to 10fps at the first scene.

If there is a way to utilize the remainder of CPU (MultiThread is Enabled already) let me know. I think the issue lies elsewhere..

Can anyone provide input?

Thanks

[LunaMoo]

Well your screenshot is pointing to a potential problem, you see you don't have an "octa core" cpu, you have two quad cores, one is 2.1ghz, the other one is 1.5ghz or as you can see on the screenshot 1500mhz. Meaning for some reason your operating system doesn't want to switch to faster cpu when PPSSPP runs, that could be caused by reaching GPU or any other limitation which your app doesn't really show, but could also just be your system not seeing PPSSPP as a heavy app which would be a fail on the OS side and don't really think there's any way to counter that without forcing it with apps requiring root as brujo55 wrote.

Also no you can't "utilize all 8 cores" - that's impossible at the same time on little/big anyway, however you will not be able to fully use 4 cores either as it for the most part depends on the game and PSP games were not designed to run on anything more than a single core cpu and that part can't be divided, no amount of work will ever change that at least no work that could still be considered emulation.

"Multithreading" option get's rendering on separate thread. Thread does not = core, your OS controls that. It also does not mean a speedup, those threads still have to communicate with each other and whenever one has to wait for another it get's worse, results will differ between hardware and games so taking other people settings is extra bad with that option. Also it's rather buggy, so if you're using it all the time, definitely try disabling it, it's surely not an option to keep activated all the time for every game. Also some of the issue it causes could possibly corrupt memory, so would recommend restarting emulation and not using savestates made with it activated as those keep all kinds of bugs by design.

[Bananaclawz]

No, don't use savestates.

But there is a way to have single core emulation operate on multicore machines utilizing additional cores? Just look at PCSX2 Emulator.

PS2 uses a CPU of 299 MHz, single but needs all my Quad Core I2700K at 4.2 GHZ to operate, where Single Core will be 1/5th potential Emulation?

With a GTX 970 GPU this still being required?

So, curious.. I appreciate your insight and will review 2nd Quad..

Would like to hear more detail?

[LunaMoo]

PCSX2 will only use all of your cores for software rendering. It has additionally a speedhack to run VU1 on separate thread, PSP doesn't have anything like that.

Windows is bad example, PCSX2 without above settings gives 1 very heavy thread(EE+VU), 1 medium thread(GS) and UI which is the typical situation. This does not divide evenly as you say, windows just likes to show off, it cannot actually divide it.

[TkSilver]

Best case scenario would be one thread per each emulated chip or part of a complex chip (like the PS2's emotion engine), but in reality even if cores share cache and other reasources it usually ends up with a performance decrease not an increase. There can be performance benefits for offloading emulated gpu code onto a real gpu over a CPU core, assuming that you have an api capable of handling the correct functions.

As far as the S6 goes and specifically the process scheduling, that is handled in android by the governor. I would highly recomend you do not screw around with this unless you.... A. Know what you are doing B. Do not mind screwing up your over $500 smartphone to get a few extra fps in an emulated psp game C. Understand the simple idea that the people who spent millions to develop the device in your hands probably have a very good reason it is set up like it is (usually battery life and heat) and changing core things like the governor can cause your battery life to drop like a rock or your phone to damage itself with heat. (If you were going to tweak it to perform slower there woukd be less worry and risk asides from screwing up and permanently bricking your phone)

If none of these things bother you then the XDA forums for your specific device will be the best place to get more detailed advice.

[Bananaclawz]

TkSilver,

Not sure if you saw thread but i'm fully aware of Governing capabilities. I disabled all Permission associates and SetCPU is set to Max only when using PPSSPP.

To add, PCSX2 I only have "Enable Multi Threaded" checked and not the CPU Hacks as mentioned above. That option is available for 3+ Cores. No hacks enabled.

If it's hack related I CAN double check to confirm, but no hacks, Jak and Daxter + All PS2 games run at maximum.

Sorry, for burden just appreciate your thoughts and would like to isolate slow downs :/

[LunaMoo]

@Bananaclawz there's no such thing as "Enable Multi Threaded" in PCSX2, it's Multi Threaded VU1 ~ MTVU in short and it IS a speedhack which as a matter of fact does break some games, I wasn't into ps2 emulation for a while and can't give an example, but I think pcsx2 devs should by now have a decent list of games broken by it as the option exist for quite a few years. Also it's not "enabled" for 3+ cores, but "recommended" in such situations, however as a matter of fact most of the time it will not give any advantage when having more than 2 cores since while it pretty much puts a VU1 to separate thread which can get heavy, in many games EE thread will still be around as heavy as VU1+GS threads combined. So yeah 2 fast cores will often have same results as 4 cores assuming architecture and clocks would be constant and background load irrelevant. And 3 cores is really maximum it will ever put a heavy load on without software rendering which really doesn't count, most users never use it anyway.
If you want to read how MTVU was possible and why it works, find "Cottonvibes" dev blog(if it even still exist;p), or some of his posts about it somewhere around pcsx2 forum(althrough he left the team few years ago).

Either way option like that will not happen in PSP emulation since it's different hardware and I don't really think it would be needed either. PPSSPP is already very light/fast and cpu emulation is rarely if ever a bottleneck in psp games(I guess it would be on new iOS, but that's only due to apple killing emulation on their devices), most of the time your device gets limited by graphic driver overhead and poor implementations of gles extensions and this is where vulkan backend could be like a cure for cancer bringing even bigger performance differences that it does already on pc's. However that's still the future as nobody could make it work on android likely due to again poor/buggy/late driver support.


What I really want to say by even discussing this is that neither lack of heavy multi threading is a problem of psp emulation nor some magical support for it could ever solve anything. Sorry to hear people have performance problems even on devices that should be powerful enough, however "utilizing more cores" is not an answer.