Macbook is my problem? If so, i3 4130 vs Pentium G3258

[CamChowdah]

Thanks in advance for your help. Here are my Macbook specs:
Core i7 2.9GHZ
Intel HD 4000 Graphics
(and 8GB DDR3 RAM)
OSX 10.9.4; running Dolphin 4.0
OoT Master Quest hangs / freezes very frequently for me (but otherwise runs smoothly, ~60fps), and Sunshine / Madden 2004 run incredibly slowly (~15fps - these are the only games I've tried; I'm mostly concerned with OoT). I've done a fair amount of research but can't find anything conclusive - are my integrated graphics the problem here? Maybe OSX? I thought my CPU would be sufficient for Dolphin.
If this is the problem then I need to build a cheap PC for Dolphin - It seems most people have recommended the i3 4130 or the Pentium G3258. I'd like it to be strong enough to play SMG.
Is the i3 worth spending the extra money on to leave the option of (more demanding) PC gaming on the table?
Can I cheap out on a mobo (~$50) or will I need to get something decent (~$100) (for OCing)?
Lastly, any input on GPU? I'd like to go really cheap on that too, if possible, and upgrade later if I get into any PC games.

[yl-smash]

You need to offer more information about your cpu. We need the model number. Also use the latest dev builds instead of stable version, they are much faster. Buy the G3258 with a Z97 mobo (aka dont cheap out) no question. You can easily OC the G3258 to 4.2 on stock cooler and it is one of the best cpu's for dolphin. Should run many modern games too as they are more reliant on GPU. I would go for a GTX 750 ti, it is pretty much the best for price/performance.

[AnyOldName3]

It's also worth remembering that once overclocked, the anniversary Pentium will be pretty much as fast as any i3 in heavily multithreaded applications, and much much faster in single and dual core applications, such as Dolphin.

[CamChowdah]

Thank you for the help! CPU model is i7 3520M. I tried the newest Dolphin and noticed little / no difference. Are the integrated graphics likely my problem?

[LordVador]

You have no chance to run demanding games with that CPU (I'm thinking of Madden games for example).

And I second AnyOldName3. If you plan to upgrade you should forget i3 processors :p

[CamChowdah]

Well that's disappointing in that I need a new computer, but it's great to not worry about the decision any more.. and it's great that the Pentium will work so well! I thought I would need to spend much more on a CPU.
I'll plan on getting a cheap GPU, Pentium G3258, Z97M mobo, OC to 4.2GHz. Thanks!

[AnyOldName3]

As it's a low power chip, what with only having two cores, you'll probably find it goes higher than 4.2 before you run into any issues with heat or instability at safe voltages. 4.5 GHz might be a better target.