Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Apple Launches Thunderbolt-Equipped iMac Lineup
Apple has recently announced the release of a brand new lineup of iMac models which has been designed to run at a speed of 3.4 GHz and has been eventually powered up by the next generation processors of Intel Core i5 and Core i7. This new generation model also offers complete support to the application of Thunderbolt, which is a high speed connection interface of peripherals that was initially made a part of the MacBook Pro lineup of Apple released earlier this year.
The new model has an associated watchword of ‘performance’ which can be mainly associated with the improvements in the processing line, Thunderbolt ports as well as the architecture of graphics.
Specifically, talking in terms of processors, Apple has seen a tremendous shift to the Intel’s Core technology of second generation which has been given a code name of Sandy Bridge for the iMac lineup. The vice president of the hardware marketing of Apple has claimed that the best thing associated with Intel is that it tends to tightly engineer the graphics section, the memory controller of the system, the cache and the processor on to a single platform. Through this engineering, the iMac system will be capable of accelerating the transfer of data between processor components that might result out in some quite impressive performance aspects.
In addition to these core areas, the up gradation of the processor has also enabled a transition to the quad core, which was the old processor architecture to the latest architecture which is said to be more than 70 percent faster than its predecessors.
Apart from processors, there are also several other aspects within which the iMac has seen drastic improvements. The lineup of desktops has now been sported to the latest generation AMD Radeon HD discrete graphics processors. This high quality Radeon HD 6790 M shows off 1.3 Teraflops of performance and is considered to be up to 80 percent speedier than its last generation family members. This technology has been described by the company as the Mac Pro class graphics which has been claimed to be the first time ever that the same performance levels has been made part of the Mac Pro as well as in the iMac lineup of Apple.
In case of external connectivity aspects, the iMac up gradation boasts the same. The ports of Thunderbolts that was introduced in the latest MacBook Pro line of Apple launched in February. The application has been co-developed by Intel Corporation and provides two bi-directional channels that have the ability to transfer data at 10Gbps each which is said to be 12 times faster than the theoretical maximum of the program of FireWire 800. Moreover, the technology has been designed to be based on the PCI Express protocol which is used by most Mac system for the purpose of internal I/O.
The smaller version of iMac models holds a single Thunderbolt support whereas, the larger model has two of them which mean that the users of iMacs will have in total 10Gbps channels. From this, the 27 inch iMac model will have the provision, for the first time to drive two external displays which is in addition to the previous high speed peripherals.
The latest up gradation in the system came out with four basic configurations. Two 21.5 inches models having a 2.5GHz and 2.7GHz Quad-Core Intel processor of Core i5 and i7 along with two 27 inches models having 2.7GHz Quad Coe Intel i5 as well as 3.1 GHz Quad Core Intel i5 is been made part of the up gradation.
The lower end 21.5 inch version has a 500GB hard drive along with an AMD Radeon HD 6750M having a 512MB of video RAM, whereas, the more powerful 21.5 inch settings holds an ITB drive along with an AMD Radeon HD 6770M with 512MB of video RAM.
Some additional inclusions of build to order options are 2TB hard drives, 16GB or DDR3 memory with an additional 256GB of solid state drive alongside of the system’s main drive.
Moreover, the latest model of iMac is also meeting the standards of Energy Star 5.2 and has also received EPEAT Gold rating. The operating system is constructed on components that are mercury free, OPVC, arsenic along with the facility of brominated flame retardants.