Extremely slow performance - What am I doing wrong?

[Fidelio]

I'm new to Dolphin but consider myself pretty technical. I was finally able to get the new Wiimote with built-in Motion Plus (RVL-CNT-01-TR) working on my system (using the advice in this thread), but the problem is that the two games I've tested run incredibly slow, to the point of seeming to be in slow motion, with frequent frame skipping and audio glitches.

The two games I've tried are SMG1 and Skyward Sword.

I have a 13" Macbook Pro but am hard booting (Boot Camp) into Windows 7 Ultimate 64-bit.

My specs:
Proc: 2.3 GHz Intel Core i5
GPU: Intel HD Graphics 3000 512 MB
RAM: 8 GB 1333 MHz DDR3

As detailed in the above linked thread, I'm using a revised Dolphin 3.0-433. Apparantly these were the only changes made to it (I have no idea what this means, but it works with the Wiimote I have):

Code:

IOWin.cpp, line 128:
static int VIDLength = 4;
static int VID[4] = {0x057E, 0x0001, 0x0002, 0x057E};
static int PID[4] = {0x0306, 0x0002, 0x00F7, 0x0330};
IOWin.cpp, line 460:
const std::wregex wiimote_device_name(L"Nintendo RVL-\\w{3}-\\d{2}(-\\w{2})?");

I use the default configuration, save that the framelimit is set to off. I'm in the Direct3D9 setting. Even running in 800x600 is unplayable.

At first I thought it might have been that I was reading the .iso off an external drive, but this wasn't the case. Then I thought using an alternate display was affecting it (as it sometimes does with my Steam games). Perhaps it could be lack of HD space (19GB free of 56GB), but that seems silly. I run the Batman Arkham games (Steam) just fine, so surely my specs can handle SMG? I'm guessing it has to do with the GPU or the Dolphin build.

So tell me, what am I doing wrong? What do I need to do?