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Grant64
July 11th, 2003, 11:43
Just a fun query really! Cyrus has already said that Icarus is slow even on high end systems
What sort of speeds do you think will be required to emulate PS2 GC and XBox emus?

Lemmy
July 11th, 2003, 11:56
Gamecube with GOOD (well maybe really good) dynrec would probably need a 3 ghz plus a direct3d 9 card (pixelshaders 2.0 would help alot cause of its advanced gfx). But 4-5 ghz would probably be more realistic.

XBOX something around 1 to 2 ghz, cause dynrec should be easier to do. But not an expert there.


I guess for PS2 you'd need something around 3 ghz.


Those are all my guesses. It highly depends on the quality of the emulator and the power of the systems which are difficult to estimate for me.

cheers

Grant64
July 11th, 2003, 12:17
Interesting - Doesn't the PS2 use two processors like the Saturn? I may be totally wrong, but that would be hell. What about the Dreamcast?

Tagrineth
July 11th, 2003, 17:49
PS2 uses three processors. It's going to need a LOT of power to emulate.

Lemmy: GameCube uses a PowerPC core, why would a dynarec be used? It'd be a recompiler just like any PowerPC, MIPS, 65816, etc... emulator.

Lemmy
July 12th, 2003, 13:05
dynrec = dynamic recompilation = recompiler

:)

The Khan Artist
July 14th, 2003, 13:38
Isn't CXBX a sort of virtual machine?

Remote
July 14th, 2003, 13:46
I guess the CXBX progress page has a pretty good explanation of what it is and what it isn't...

www.caustik.com/cxbx/

Kahenraz
July 15th, 2003, 22:52
I think that the real challenge with gamecube emulation is that gamecube is based off of the mac's whatever-you-call-it processor. o.O

nephalim
July 16th, 2003, 02:24
Question: Isn't the XboX using (relatively) standard PC chips? If that's the case, wouldn't emulation be simple, other than "cracking" the system?

Reznor007
July 16th, 2003, 04:21
Truly emulating Xbox will be VERY hard. CXBX basically just hacks the games into running on your PC, it doesn't really emulate the Xbox though.

Emulating Gamecube will be difficult because of the undocumented video chip and PowerPC chip, which is difficult to emulate.

PS2 is just another MIPS based system though, and just look at how many MIPS emulators are around. Emulating the vector units will be hella slow though.

Stezo2k
July 16th, 2003, 10:07
Truly emulating Xbox will be VERY hard. CXBX basically just hacks the games into running on your PC, it doesn't really emulate the Xbox though.

yeah but its just the same outcome though, the game will play on ya pc, plus emulating the xbox will be very difficult, and will take a high spec system

Tagrineth
July 16th, 2003, 17:54
Reznor007: Another problem with emulating the PS2 is framebuffer effects, plus any games that really abuse PS2's monstrous fill rate (MGS2, for example) will chug horribly even on an HLE renderer.

ector
July 21st, 2003, 13:21
Reznor007: Another problem with emulating the PS2 is framebuffer effects, plus any games that really abuse PS2's monstrous fill rate (MGS2, for example) will chug horribly even on an HLE renderer.

I'm pretty sure your average ATI Radeon has a far more monstrous fillrate than even the PS2 :)

SurfPA
July 21st, 2003, 14:11
uhh this is kind of related....but how similar is xbox to your standard pc. the reason im asking is because im wondering how much "emulation" will be needed to fully emulate an xbox.

blizz
July 21st, 2003, 19:29
somehow I'm reminded of the "there will never be an N64 emu" ********.... and then came UltraHLE ;)

alexa999
July 21st, 2003, 19:33
somehow I'm reminded of the "there will never be an N64 emu" ********.... and then came UltraHLE ;)

The same thing is happening with Dreamcast. :plain:

nephalim
July 22nd, 2003, 01:57
You know you're "old school" if you remember all the "there will never be an N64 emu" rukus. :) HLE truly changed the world of emulation. It's good by allowing more complex systems to be emulated, such as allowing system as old as the N64 to be run on a standard system, but it's bad (IMHO) by allowing emulation of systems that are still in their prime. I think i'm the only one who is hoping next-gen emulation takes a few years before commercial games are playable (by very conservative standards.)

Tagrineth
July 23rd, 2003, 08:28
What's funny, is, ZSNES for example had been HLE'ing its graphics engine for a long time before UltraHLE made the practice popular :)

ector
July 23rd, 2003, 10:14
You could say that, but UltraHLE did some emulation at a much higher level, hooking OS functions that the dynarec couldn't handle and redirect them to C functions that performed their functions. From what i've understood, UltraHLE didn't bother to emulate the RSP co-processor either, but simply recognized the highlevel commands sent to it, and translated them to Glide.
Zsnes doesn't do anything similar, it's simply impossible on the SNES since there is no common OS code in games or co-processor with microcode. It would perhaps be possible to HLE the sound coprocessor in a few games but compatibility would drop, just like UltraHLE.

Tagrineth
July 24th, 2003, 19:39
ector, what I mean is, it doesn't attempt to emulate the SNES's graphics engine as it should be run, it's instead done in a completely different way. Like 100% different.

The Khan Artist
July 24th, 2003, 23:47
ector, what I mean is, it doesn't attempt to emulate the SNES's graphics engine as it should be run, it's instead done in a completely different way. Like 100% different.

Not HLE. HLR. High-level Rasterization. Like PSX emus do.

Right?

Tagrineth
July 25th, 2003, 01:46
Not HLE. HLR. High-level Rasterization. Like PSX emus do.

Right?

Kinda. Except SNES is 2D. =)

nephalim
July 25th, 2003, 05:53
ector, what I mean is, it doesn't attempt to emulate the SNES's graphics engine as it should be run, it's instead done in a completely different way. Like 100% different.
different != HLE, AFAIK.

Cyberman
July 25th, 2003, 18:32
GameCube:
The biggest challenge on this will be the same problem with the N64 system.
Nintendo used custom opcodes on the PPC core for graphics and sound aceleration.
Obviously you can't run the minidisk carts in ones PC such is life.

PS2:
Buy Linux for it and you will have all you need for the video end of things.
Anything else would require you to reverse engineer there wrapper modules to find out how the hardware is used, which violates the EULA. <dmca strikes again (sigh)>

XBOX:
A glorified PC with a custom GF3 GPU
Since MS was kind enough to use the embeded version of DirectX it's probably easier to translate the DirectX interface calls to ones OS. DX 8 9 or what have you. Might require some tweaking though. I need to look at the CXBOX site and see what they are doing in terms of the binary images though. It's not likely they are using windows compatible executables in it ;)

Cyb

Tagrineth
July 25th, 2003, 18:45
GameCube:
The biggest challenge on this will be the same problem with the N64 system.
Nintendo used custom opcodes on the PPC core for graphics and sound aceleration.
Obviously you can't run the minidisk carts in ones PC such is life.

Some aspects of Flipper are going to be evil though, for example the TEV.

ector
July 25th, 2003, 19:06
Yeah the TEV (gamecube's "pixel shaders", not as programmable but still incredibly flexible) are quite evil, but not nearly as evil as the completely undocumented DSP :) It should be possible to emulate the TEV 99% on a Pixel Shaders 2.0 capable graphics card by generating and caching pixel shaders. That won't be easy though, for whoever dares trying :)
There is useful information about the graphics commands in the patents, albeit scrambled into lawyerspeak :)

The extra PowerPC opcodes won't be much of a problem as they are documented.

nephalim
July 26th, 2003, 00:24
Off-Topic, but what's the difference between pixel shaders 1.2 & 2.0? I think the vertex shaders version on my machine is higher than the pixel shaders (I have 1.2, Radeon 9000,) but i'm not sure of the number there.

Don't tell me I have pixel shader support but because it's not pixel shader 2.0 (said sarcastically,) it's useless? :doh:

Reznor007
July 26th, 2003, 14:38
I'm pretty sure your average ATI Radeon has a far more monstrous fillrate than even the PS2 :)

PS2 has a 2.4 gigapixel fillrate. However, any multitexturing requires multipass. Radeon [email protected] is 3.2 gigapixel, so it's not a whole lot faster(though at multitexturing it would rape PS2).

Reznor007
July 26th, 2003, 14:40
Kinda. Except SNES is 2D. =)

What exactly is HLE'd on SNES? The hardware is all tilemaps and sprites, and is handled as such. ZSNES even works on a scanlines basis as the real SNES does, changing modes per scanline.

Tagrineth
July 26th, 2003, 23:49
Reznor: That's because it has to do scanlines, else some games which change parameters (say, for Mode 7) halfway down the screen can still work. I wouldn't argue with me on this, though. I've talked to PAGEFAULT about this.

And... another thing, PS2's GS is optimised for really small triangles. Radeons... aren't.

nephalim: Radeons (not the original, but 8500 and better) support pixel shaders 1.4 and vertex shaders 1.1. Radeons above 9500 support PS and VS 2.0. The difference with PS is the amount and types of instructions available... there's also a big precision difference (PS2.0 opens the doors to full floating-point precision). But realistically, games won't be using many 2.0 shaders for a little while, since most of the time you can still pull off equivalent effects with 1.2 (GeForce3, 4) and 1.4.

Reznor007
July 26th, 2003, 23:59
ZSNES does work per scanline, that's why so many games work. In fact there was a discussion about this recently about using OpenGL/D3D for filtering and how it would have to draw one 2 polygons per line as SNES can change modes per scanline.

ZSNES is LLE, everything is done at an opcode level. N64 is HLE, as the RSP isn't fully emulated, some parts are just simulated.