PCSX2 vs PPSSPP

[applepiejr]

lets expand our minds and bust some myths

its no secret PPSSPP runs very well and emulates very well while PCSX2 on the other hand though emulates pretty well in recent versions still runs like total ass for a lot of people.

why?

common statements and ideas with counter arguments and detailed explanations:

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"PSP is much weaker than the PS2 and therefore easier to emulate!"
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well, sorta, but also not really…

PSP specs
CPU - 333 MHz, 3.6 GFLOPS
GPU - 166 MHz, 664 MPixels/s, 33 MPolys/s
RAM - 32 MB (64 MB for later models) (8 MB allocated for the OS), 2.6 GB/s
VRAM - 2 MB, 5.3 GB/s
Screen - 480 x 272

PS2 specs
CPU - 299 MHz, 6.2 GFLOPS
GPU - 147 MHz, 2.4 GPixels/s, 66 MPolys/s
RAM - 32 MB, 3.2 GB/s
VRAM - 4 MB, 48 GB/s
Screen - 640 x 480 (some games run as low as 512 x 448)

adding Xbox for good measure since it was often considered to be more powerful than the PS2

Xbox specs
CPU - 733 MHz, 3 GFLOPS
GPU - 233 MHz, 933 MPixels/s, 116 MPolys/s
RAM - 64 MB (unified), 6.4 GB/s
VRAM - n/a
Screen - 640 x 480

(still adding/understanding the specs to ensure accuracy of my statements)

first disclaimer would be that most of the numbers are not directly comparable. this would include clock speeds since their respective processors use different architectures, and theoretical numbers such as max polygon counts can vary depending on the method used to ascertain those numbers. and lets be honest, since most of these numbers come from Sony/Microsoft they should be taken with a grain of salt. but we have to go by something...

so specs indicate that the PS2 has twice the power in certain areas while the PSP is competitive in other areas. this wouldn't be too surprising as the gap is actually much worse for a PS3 vs PS Vita scenario but thats a story for another time. anyway even if this was true, in practice PS2 games don't look or run twice as good as PSP games (the God of War games are a great example). some of this is because of the resolution difference. PSP only renders 480 x 272 pixels whereas the PS2 renders up to 640 x 480, which is twice the pixel count. rendering at the lower resolution takes a huge load off the PSP and allows it to catch up to the PS2, at least as far as the GPU is concerned because resolution is a job for the GPU.

as for the CPU, its complicated. yes we are looking at a raw 3.6 GFLOPS vs 6.2 GFLOPS but GFLOPS isn't everything when analyzing CPUs, if comparing to the Xbox's 3 GFLOPS is any indicator. regardless, this is the biggest slowdown for most people using PCSX2, emulating the PS2's CPU aka Emotion Engine (EE).

no the PSP wasn't as powerful as the PS2 but its not that far off either. so although this does count for something as far as power needed to emulate both systems, its also far from being the main reason or the only reason for the performance gap between PCSX2 and PPSSPP.

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"PCSX2 is poorly optimized and the devs suck!"
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no. i'm sure the PCSX2 devs are talented and work hard. but there is definitely more work to do.

resource utilization on PC (Dual Core CPU with hyperthreading and DirectX 11 GPU):

PCSX2 v1.4.0 Direct3D 11 (multithreading enabled)
CPU: 65%
GPU: 80%

PPSSPP v1.2.2 Direct3D 9 (multithreading enabled)
CPU: 50%
GPU: 85%

this is average max usage for situations below 100% speed in CPU and GPU heavy areas

it is interesting to see that the emulator with far better performance actually uses less of your hardware's resources. this also means that both emulators still have quite a bit of power left to take advantage of on the Windows platform.

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"PS2 has more complicated hardware compared to the PSP"
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this is true to some extent. long story short the PS2 has many sub systems that must be synchronized with each other. thats one reason PCSX2 still doesn't have a proper frameskip function. and thats really unfortunate because frameskip would allow people such as myself who are only average about 66% of full speed in PCSX2. it wouldn't be the smoothest looking experience but games would actually be playable and fully functional. heres hoping that option comes to fruition some day and the program receives further optimization.

the thread is still work in progress

thoughts?