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GSDX scaling and CPU relation?
#1
Guys I've been wondering this, does using higher scaling on GSDX require more CPU power?

I have 4850 1GB edition so I though it was sufficient but in some games even putting 3x scaling will drop fps severely while using native or 2x scaling net me full speed. My CPU is Phenom II X3 720@3.2GHz btw.
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#2
Nope. It uses up a very small extra portion of CPU power but it is 99% GPU power. Your test results show that the 4850 can't handle those resolutions for the games you tested.
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#3
Hmm I suppose you're right, I guess with high scaling GPU matter more (though 4850 being insufficient rather come as a surprise). More thing to invest, worth it though. >.<
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#4
(07-06-2010, 09:18 AM)Bositman Wrote: Nope. It uses up a very small extra portion of CPU power but it is 99% GPU power. Your test results show that the 4850 can't handle those resolutions for the games you tested.

Actually it should be so and most work befalls really on the GPU, still it imposes a heavy toll on an already overloaded CPU as well, so it would not matter if one has a 5870 or a 480 there, he still get low fps from the bottlenecked CPU.

Albeit not directly acquainted with the actual code, i dare to suppose it being caused by the way PS2 uses the EE and VUs altogether with the GS itself and that need to be emulated.

That is particularly noticeable because it is the EE that goes skyrocket when the scaling under bottleneck occurs.
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#5
Is it possible to know what the actual resolution is for different configs? i.e. is 'native' always the same (and x2 is twice x and y, = x4 pixels?)? or does it change with each game? To my naked eye, it seems 'native' always looks the same. Also, does the resolution refer to the framebuffer?
[i7-3630qm/gt650m-2G/Win-7] [i7-4500u/R.HD8850m/Win-8.1] [2010-MBA/OSX-10.9.x]. Scroll smoothly with SmoothWheel for Firefox.
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#6
It's the same each way. If the EE is stalling, you could set x5 on the scaler (subsequently causing huge GPU usage) but still get the same FPS since the GS is waiting on the EE. Vice versa is also true, meaning on a GS limited game, if you keep the same resolution that maxes out your GPU, using a faster processor will have no actual effect on FPS since the EE is still waiting on the GS, which loads your GPU and not your CPU.

So in naoan's case, since his FPS are fine in native and 2x scaler resolutions, it is obvious that at 3x and above he is GS limited, meaning overclocking his CPU or getting a faster one will have no impact on speed at that point.

Quote:Is it possible to know what the actual resolution is for different configs? i.e. is 'native' always the same (and x2 is twice x and y, = x4 pixels?)? or does it change with each game?
It's different for each game but usually something around 512x512. Older GSdx used to print it on the title bar, not much space for that in the newer one Tongue 2x,3x etc are multiples of the native resolution each game has.

Quote:Also, does the resolution refer to the framebuffer?
What do you mean? It's the resolution the textures are actually rendered at
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#7
Yeah, it refers to the most likely framebuffer. The GS is a bit funny in that regards Tongue2
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#8
Would selecting different PS2 display settings (default/480p/1080i/PAL=576i?/16:9) affect PCSX2/GSdx/GPU performance in any way? I tried (GT4, SotC) but couldn't notice a substantial difference (though 'native' at 1080i does seem higher res than the 480p native in GT4), but is there a theoretical difference?

Also, I couldn't quite understand how is interlacing treated (I'm pretty knowledgeable about interlacing, but not so about the PS2). I would guess that it could possibly be bypassed for 'pure' 3D output (=no deinterlace needed), but might affect outputs that have to be 'composed' somehow (framebuffer effects?), and might affect 2D 'sprites'.

But on some games I didn't see interlacing artifacts at all (Ico, SofC, MGS2/3, GOW1/2), while on others (GT3/4) it's clearly interlaced unless set natively to 480p. Ico ans SotC specifically clearly have framebuffer effects (blur, HDR) but I couldn't notice any interlacing even when not selecting progressive scan (SotC), and Ico doesn't even have this option and still no interlacing artifacts.

And one last thing, deinterlace mode in GSdx is not reflected at the window title as it used to be prior to 0.97.3113 (still the same in recent svn builds too), not when changing via GSdx config panel and not when using F5. It always says 'Interlaced (Frame)'.
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#9
Bump.. ?
[i7-3630qm/gt650m-2G/Win-7] [i7-4500u/R.HD8850m/Win-8.1] [2010-MBA/OSX-10.9.x]. Scroll smoothly with SmoothWheel for Firefox.
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