Never doubt a firmware update.
On Wednesday, Apple released version iMac EFI Firmware Update 2.1 for its just-released late 2013 iMacs. The update, an 8.7 megabyte download, offers the following fixes and changes:
– This update addresses an issue which may cause a black screen to appear when installing Windows 7 or Windows 8 using Boot Camp Assistant if both an external optical drive and USB thumb drive are connected to the system. This update also ensures that the system will boot by default into OS X after installation of Windows 8.
The update requires a late-2013 iMac running OS X 10.8.4 or later to install and run and can also be downloaded and installed via OS X’s Software Update feature.
If you’ve tried the update with your new iMac and have any feedback to offer, please let us know in the comments.