IMac – Control iMac and LED Cinema Display Brightness Simultaneously

I have heard a few people complain of brightness resetting on reboot. Traditionally brightness settings are stored in the PRAM, which you can reset via ⌘⌥PR on booting. I would be interested to see if it gets "stuck" on a brightness setting that you do not wish to have after resetting the PRAM.

I've looked into this in the past, and from what I know, you have a few options:

1. I'd never really recommend it, you can get a usb adaptor that essentially adds another display port to your computer. Make sure the one you pick is Mac compatible - there are some that exist.

2. DualHead2Go is an interesting product that emulates a single double-wide monitor to your computer. There are some catches:

   • There is a maximum resolution the device supports
   • It works best if the monitors are the same dimensions and resolution
   • It's currently ~$230
   • The computer doesn't see the monitors separately, which means that when you configure/use it, it will act accordingly. If you put the menubar on the external 'monitor,' it will stretch across both; maximized windows will be two monitors wide etc.

3. I can't find anything to back it up at the moment, but at one point I do believe I saw an ExpressPort/34 video card or a breakout box for a PCI card. The only thing I can find now is XGP, but I'm near certain I saw a Mac-specific solution at one point.

Each has its benefits and drawbacks. If you're not on a tight budget and your monitors will work for it, I'd recommend the DualHead2Go.