iMac SMC Firmware Update 1.1
Apple has released iMac SMC Firmware Update 1.1, which is recommended for recently released iMac models that have been configured with PCIe-based flash storage (see “Apple Updates iMac with Faster CPUs and 802.11ac Wi-Fi,” 24 September 2013). The release improves the Power Nap feature in OS X 10.9 Mavericks so that it runs silently while your iMac is sleeping without spinning the fan. (Free update, 921 KB)