Ok, so I reinstalled Windows once more but in a, not that different, but more complete way. Here's what I've done:
- Using Boot Camp, I removed the Windows partition;
- Right after it was finished, I shut down the MBP, reset the SMC and PRAM;
- Turned it on again, ran Boot Camp and created the USB disk, downloaded the drivers and created the partition again (I simply left all the checkmarks checked) - used a Windows 8 ISO btw;
- After that was done, the MBP rebooted and started installing Windows. I just let it do it's thing. Once W8 finished the Installing Apps, Setting Up the Computer etc etc, the drivers started installing right away. After that it rebooted;
- I installed Windows updates;
- Updated NVidia GPU drivers to the latest ones;
- Installed Malwarebytes;
- Installed FIFA 13.
Once I ran it I knew there was a difference. The stuttering was gone! Now, I don't want to celebrate, reboot into Windows and face the same problem. I'm not even saying that the throttling is gone (once it gets to certain temperatures) but my problem* is gone.
Now, if this is really fixed, this is what I think.
EFI update and 10.8.3 came out on the same day. With 10.8.3, Boot Camp was updated to support W8 so I decided to just install the drivers on top of the ones I had. That was probably when the issues began but I didn't connect the dots.
I reinstalled Windows more than twice before today but never using Boot Camp itself. I just created the USB install disk using Boot Camp, rebooted the MBP and pressed the Option key. Then I would choose the USB disk and install in the same partition as my latest Windows installation (formatting it). Then I'd just download the latest Boot Camp drivers to a USB stick and run setup.exe under Windows. Probably the new drivers have an issue with that. Plus, I had never seen the drivers installing right after Windows first ran. I usually had to navigate to the USB stick where the drivers were and run Setup. Today, I didn't have to do that.
I could have just gotten lucky and the issue might even return in some days *knocks on wood* but, for now, it's buttery smooth just like it was before the updates.
Give it a try and, if that does not solve it, I will still help with the email.
*my problem in particular was a bit different and, mainly, weird. The games would run at a nice FPS rate but would stutter a lot. I wasn't the same person with this particular issue so I just assumed it was the MBP acting up.
PS: I know the steps I took are really in detail but I'd like to point out exactly what I did.