Socket G1, also known as rPGA 988A (there are Socket G/rPGA 989 sockets that can take Socket G1/rPGA 988A or Socket G2/rPGA 988B packaged processors), is Intel's CPU socket for their line of mobile Core i7, the successor to the Core 2 line. It is based on Intel's Nehalem architecture which was first available for the 1366-pin "Socket B", which, like its predecessor, LGA775, uses the LGA socket configuration. Later followed the updated LGA-1156 socket, which moved the QPI and PCI-express controller off the Northbridge and onto the CPU. As a result of the lower pin count, LGA-1156 systems, and later, socket G1 systems, can only run in Dual-channel memory mode, as opposed to the Triple-channel mode which is unique to the LGA-1366 platform (and subsequent Xeon sockets). The Nehalem's mobile variant was released on September 23, 2009 in the form of the i7-720QM, 820QM, and 920XM models, followed by the i7-740QM, 840QM, and 940XM models on June 21, 2010. The newer CPUs use the new Clarksfield core, which maintained the same 45 nm manufacturing process as the desktop-based Nehalems. Nehalem received a die shrink on January 7, 2010, under the core name of Westmere. With the Intel GMA HD GraphicsIronlake core packaged onto the CPU substrate, but not integrated directly to the processor die, it goes on to create the Arrandale-based line. The current CPUs to use this package are the Core i7-6x0M series, the Core i5-4x0M series, the Core i5-5x0M series, the Core i3-3x0M series, and finally the Pentium P6x00 series and Celeron P4x00 series which were released on March 28, 2010. However, not all of these are available for Socket G1, as some of them are only available in a BGA package. They are also known as PGA988 socket processors.