Just wondering about this. Dolphin seems to run certain Gamecube and wii games very well but others the frame rate is poor on my PC. It doesn't seem to matter on my PC what I do graphically, be it native resolution and output as standard definition or upscale to 1080p I get similar frame rates so I guess the graphics side is working very well. However Some games allow 60fps and are rock steady at that and others are at unplayable frame rates.

Full frame rate awesome quality

New Super Mario Bros - wii

Mario Kart wii

Mario Kart - gamecube (not 4 player split screen, frame rate severely drops) 

Burnout 1

Burnout 2

Starfox Assault

Wreckless

Zelda windwaker - gamecube

Zelda twiilight princess -gamecube

Close to normal frame rates at times or just about playable  but other times severe frame rate drops

Turok Evolution

F Zero GX (looks amazing at 1080p)

Judge Dredd - Dredd vs Death - Gamecube

Unplayable frame rates

Call of Duty Finest Hour

Metroid Prime

What are your PC specs? Dolphin is usually very CPU bound.

No.

Emulation like the name says emulates the instructions found in the original CPU... so some instructions can have a similar instruction in the CPU that will emulate the game but others didn't have and you need to waste a lot of CPU instructions/cycles just to emulate one instruction of the original hardware.

So at the end you can have instructions that runs fine and with low CPU cost in the original CPU but that have trouble to run with a lot of CPU use in the CPU used to emulate.

So the emulation will just show the games that have high CPU use to be emulated... it can be low CPU use in the original hardware.

Can shorten that for ya Ethomaz :D

Indeed, no. Just a question that I always wanted to ask: What if you had the exact same specs as a Wii console and you'd emulate a Wii game via Dolphin? I know that you can't easily get them but hence the if.

So your theory is that certain games favour certain instructions of the cpu and will have a differnt performance level in emulation? I'm not convinced of that I think the results I have found show games that require more cpu resources are slower in emulation. It's always been stated racing games need less cpu resources as its more about throwing graphics on the screen fast and needed limited AI in the other cars and that seems to be indicated. Factor 5 and Retro studios really push the hardware of gamecube and wii and those are the weakest performing in emulation. Nintendo games typically cartoon graphics without much AI or physics engines etc perform very well. 

The PC is a humble A10 5800k with a HD6670 in dual graphics mode with a quad core cpu at 4ghz. Very cheap PC that cost about £230 to assemble.

What Ethomaz said is absolutely true. You cannot use Emulation as a measure to determine which games are CPU bound. Some games will need to be completely emulated on the CPU which might bias the results of which games are more CPU intensive.

It will make it easier (like PS4 and Xbone will be) but the emulation will always have performance penalities.

The way it works is instructions need to be "translated" when emulating.

However, it's not a 1:1 translation, some instructions need to be split-up into multiple instructions that's compatible with the host machine.
So one Instruction on a console could equate to 3-4 instructions on the PC, hence you need orders of magnitude of CPU performance to run it.

Conversely, some games may use a ton of instructions where they aren't split up as heavily.
Another game may use allot of instructions that are split up allot, thus one emulated game will require more CPU performance from the PC doing the emulating, but still use the same amount of CPU horsepower on it's original system.

Another issue is emulation accuracy, you can bring down even the fastest of PC's if you built a 100% accurate SNES emulator, most emulators however don't push for such levels of emulation accuracy, but instead find a middle ground of "Good enough".

As we've seen with the original XBox vs the PS2, that doesn't have to be the case.