Even though the Intel Z68 Express chipset isn't expected to be officially launched until May 11, Apple has already started using this PCH in its recently released 2011 iMac all-in-one systems that are now available for purchase. This was uncovered in an iFixit's teardown of the new 21.5-inch iMac that was published soon after the Apple system was announced. The chipset is marked as the “Intel BD82Z68” and is expected to be made official by Intel on May 11. Compared to Intel's previous LGA 1155 chipsets, the Z68 brings both CPU overclocking and integrated graphics support, while also adding a new SSD caching technology that is known as Smart Response. The integrated graphics support allows consumers to use the Quick Sync media engine found inside Sandy Bridge CPUs for accelerating video transcoding tasks even when a discrete GPU is present. This, however, requires a specialized driver to be installed, LucidLogix' Virtu or Nvidia's Synergy, both of which aren't supported on the Mac OS X operating system. The Smart Response SSD caching technology also isn't used by Apple's iMac's, so this leaves many wondering why did the Cupertino company decided to go this route when designing its new AIO systems. One of the reasons it could be that Apple is interested in porting the Virtu driver to Mac OS X or that they are planning on developing their own version of LucidLogix' graphics switching technology. The possible introduction of SSD caching could be another explanation for this fact, but nothing is certain at this time. The 2011 iMac all-in-one systems are powered by Intel Core i5 and Core i7 Sandy Bridge processors that are paired together with 4GB of DDR3 RAM and Radeon HD 6000M-series dedicated graphics cards. Right now, Apple is offering 21.5-inch and 27-inch models and all of these support Intel's Thunderbolt interface.