JPCSP Official Requirements?

[montcer9012]

According to this:

The PSP uses one 333 MHz MIPS32 R4000-based CPUs, a GPU with 2 MB onboard VRAM running at 166 MHz, and includes 32 MB main RAM and 4 MB embedded DRAM in total.
http://en.wikipedia.org/wiki/PlayStation_Portable

But as seem on PCSX2, as more demanding the game, then powerful resources are needed for a proper JPCSP emulation. In that order, i don't get how is that some games (Demanding ones) on JPCSP need at least 3GHz CPU to get 30/60 FPS since a PSP CPU work at 333 MHz.

In my case for example, i own an Quad Core AMD A8-3510mx running 2.5 GHz at turbo speed for each core. Sometimes 2.5 GHz is not enough to get 30 FPS. God of War for example, ran at 10-15 FPS with that speed; if i overclock my CPU to 3 GHz then GOW got a speed boost getting 25-30 FPS. I guess this subject speed is because my video card since it is ATI and everybody knows the problem between JPCSP and ATI. For sure gid15 is making a great work to fix ATI bugs, like on r2684; however, a 3 GHz CPU to run a game that work on his original console under 333 MHz CPU and 166 MHz GPU is kind of wrong.

So, my point is: Why emulators and on this case JPCSP needs 9x or 10x times the original specs of their native consoles?

[serio]

console and pc cpus are different.

consoles use their cpus to do all the rendering and instructions.

emulators have to translate them to something pc can understand, and then attempt to fake those new, emulated instructions to make it work the same. while at the same time also running windows, rendering the desktop, running all background processes and also doing it all through 1-2 general use cores (java's not good with multi core cpus, and pcs have different cpu/number of cores, so you can't make it work the same for everyone), while a psp has several of them, each specialized for specific things.

tl;dr
it needs a lot of cpu power, since it tries to translate a completely foreign, alien psp language to a native pc one on the fly.

[Zekro]

That's the way emulation works,you need a 10 times more powerful pc or console,thats why.For Example,look at the n64 emu for the psp,the nintendo 64 has 93,75 MHz while the psp has 333 MHz.For ps3 we need at least...um lets say the ps3 has a 3.2 Ghz processor so we need something 10 times better like 32 Ghz(impossible for now).I know it's kinda weird but thats how it works in emulation,even the ps2 needs a 3.0 GHz pc because it only has 294.912 MHz(yea I know).And that is only the processor not to mention the gpu

[jeremymd]

Most impressive emulator i've tried so far is dolphin. Wii has a hardware edge compared to the PS2 and if the PS2 emulator runs laggy on a certain computer, you'd expect the Wii emulator to be even slower. However that was not the case. I can play Monster Hunter 3 on dolphin with full speed 99% of the time, compared to the PS2 emu where i'd have to get used to the unstable framerates on graphic intensive games like Sons of Liberty and such.

I'm no coder, but I have good enough grasp of theory. I know emulator performance has something to do with the "robustness" of the emulator code and also the game itself, and not just about how 3d the game is but how efficient the code of the game itself is.

[montcer9012]

consoles use their cpus to do all the rendering and instructions.

If i am right, on PC the rendering work goes to video card; if that is the case, can't be implemented the language of the emulator to take those instructions to the video card instead CPU? I guess that should be the stronger problem on PCSX2 where the video card is barely used.

I know it's kinda weird but thats how it works in emulation,even the ps2 needs a 3.0 GHz pc because it only has 294.912 MHz(yea I know).

Told me that. Well, at least dev team of PCSX2 still working on a better emulation code; on January of this year people on PCSX2 forum told me that my A8-3510 won't run PS2 games even with the speed hacks; however, with the implementation of the 3 core on speed hacks now i can get 50/60 FPS. If they implemented the 4 cores usage and let more work to the PC GPU instead the CPU, i guess the emulator will be more compatible for many people.

Most impressive emulator i've tried so far is dolphin. Wii has a hardware edge compared to the PS2 and if the PS2 emulator runs laggy on a certain computer, you'd expect the Wii emulator to be even slower.

Well, i heard some time that same workers of Nintendo release the Wii documentation making the emulation development easier than SONY's console where some parts functions are keeped secret on the company; don't know if it is true but according to SONY behavior i won't be surprise.


Well, thanks for the answers. If gid15 still working like he is doing, i guess those 3 GHz won't be necessary with right emulation implements.

[serio]

they're already using the gpu for some/a lot of the rendering. try running either of the emulators in software mode, you'll see how unbearably slow it gets.

[gid15]

Which results do you get when running the demos/compilerPerf.pbp?
This is a pure CPU test (no graphics), comparing the performance of Jpcsp with a PSP.
Such a test would be required for graphics, as this is the main bottleneck for most games.
I've tried to describe in the README.txt why the graphics implementation is often slower than on a PSP:

Code:

OpenGL provides some optimization techniques for application developers when they
follow some basic principles (e.g. grouping the display of similar graphics together,
reusing the same data at each frame...). The PSP does not use the same optimization
techniques, e.g. there is no real advantage in grouping similar graphics together,
or reusing the same data at each frame. So, the PSP programmers are optimizing for
the PSP, which is not the same as optimizing for OpenGL.
The Video configuration options allow the activation/deactivation of OpenGL techniques:
they might improve some games if their programmers by chance more or less followed
the OpenGL principles, but they also might decrease the performance if the game
programmers did something completely different (which is also legitimate on a PSP).

[montcer9012]

they're already using the gpu for some/a lot of the rendering. try running either of the emulators in software mode, you'll see how unbearably slow it gets.

My point was that the GPU could do more work so the CPU will be not overloaded. Either way, i notice more GPU usage with JPCSP than on PCSX2.

Which results do you get when running the demos/compilerPerf.pbp?

A info log will not get important information so i attached 2 pictures where i force the CPU work at 2.5 GHz; one test was on 222MHz and the other one at 333MHz.

Also gid, i don't know why but JPCSP does not make my CPU work at full speed. The AMD APU's series work at a low level (mine for example, 800~1800 MHz) so it don't get warn or consume the batteries since mine is a Laptop CPU; however, when an application needs more power the CPU auto-boost to 2.5 GHz the necessary cores for the time is necessary. When using JPCSP, the CPU does not boost more than 1800 MHz; to make it work at 2.5 GHz when running JPCSP i need to set the speed with K10STAT. Any idea why the boost does not happen?

[hyakki]

Also gid, i don't know why but JPCSP does not make my CPU work at full speed. The AMD APU's series work at a low level (mine for example, 800~1800 MHz) so it don't get warn or consume the batteries since mine is a Laptop CPU; however, when an application needs more power the CPU auto-boost to 2.5 GHz the necessary cores for the time is necessary. When using JPCSP, the CPU does not boost more than 1800 MHz; to make it work at 2.5 GHz when running JPCSP i need to set the speed with K10STAT. Any idea why the boost does not happen?

montcer9012 instead of setting it through k10stat have you tried windows power management under
Control Panel -> Power Options -> Change advanced power settings -> Processor power management and set the Minimum processor state, set to 100%

You might want to look into disabling 'core parking' too (search google for more info), windows (7-8) will park cores to save a tiny amount of power and force most of the load onto the first core until there is enough demand to unpark the other cores (you cpu has to support core parking, if it does windows enables it automatically, also I'm not sure if amd processors have this.)

Quick way to check is under task manager -> performance click Resource monitor -Click CPU look on the right side of the screen for Parked next to the core name
    < Parked - Unparked>    

[montcer9012]

montcer9012 instead of setting it through k10stat have you tried windows power management under
Control Panel -> Power Options -> Change advanced power settings -> Processor power management and set the Minimum processor state, set to 100%

Thanks for the suggestion, but my AMD is a rebel and he does not do what Windows told; even i set the PowerPlan on High Performance taking care CPU is on 100% usage like you say, CPU stay on 800~1800MHz. So, to be sure he works at top i use Catalyst Control Center to set it but CCC only let me force the maximum at 1800 MHz; the 2.5 GHz boost activate automatically.

About the parking thing, mine CPU does not do that or is not activated.

And about your test resuly, is huge different from mine hahahahaha. What model is your CPU?