Why does the GBA emulator run slow on the i7 iMac

I pulled out my old monitor to test the very small list of SNES emulators.

• zSNES uses DirectX calls that ignore Windows' own monitor logic, which requires that zSNES handles multiple monitors itself (which it doesn't). Without a rework of its rendering code (which has been promised and undelivered since 2006, at least), zSNES is out of the running.

• SNES9x though handles multiple monitors fine, and under the Emulation menu it has Pause When Inactive on by default. Turning that off makes it continue emulation when it doesn't have focus just fine, at least in the version I'm testing (v1.53 W64) on my hardware. (It's possible that it has sound issues that are hardware dependent.) However, I appear to be suffering an odd bug where SNES9x will recognise my gamepad when I'm configuring the controls, but ignores them during emulation, so I can't directly confirm that input works when it doesn't have focus. In theory it should.

• higan is a bit idiosyncratic in a few ways – you have to "import" the cart if it isn't a .sfc format ROM, and it offers a very granular degree of control over video and audio sync that doesn't give an optimal out-of-box experience (there is an AV timing wizard to mess with) – but my testing confirms that its configuration options for background emulation and background input work just dandy with my gamepad and my second monitor. It won't run in fullscreen on the second monitor – attempting that fullscreens it to the main monitor. You'll also need to make sure that the controller config not only uses the gamepad, but that you also remove all the keyboard bindings as well, since otherwise higan will respond to your typing while your friend tries to play.

I haven't tested OpenEmu or NO$SNS yet, but if higan or Snes9x v1.53 doesn't do it for you, I can track those down too.

I just experienced the same thing when I was playing around with Screen Sharing (from A I looked at B, and when I tried to connect from B to A, A's screen suddenly got a blue tint). Changing resolution back and forth a couple of times fixed it.

This was also on a MBP 13", bought in april 2012.