Intel Core i7-3840QM socket: Socket G2

What the Core i7-3840QM is

Intel Core i7-3840QM is a quad core Ivy Bridge mobile processor that Intel released in September 2012 as the top locked QM quad. It runs at 2.8 GHz base with turbo to 3.8 GHz, with 8 MB Intel Smart Cache and Hyper-Threading for 8 threads. Power is rated at 45 W on a 22 nm process. High base plus large cache made it the choice for socketed mobile workstations that could not use XM power.

Graphics are Intel HD Graphics 4000 at 650 MHz to 1300 MHz per ARK. The block covers office displays, while most 3840QM laptops add a discrete GPU for professional 3D work. Memory is DDR3, DDR3L and DDR3-RS at 1333 or 1600 MT/s for up to 32 GB.

Late 2012 laptops pair it with QM77, dual SODIMMs and discrete graphics. All core work sits near 2.8 GHz, which is unusually high for a mobile quad of the period. The How to find your CPU socket type guide helps confirm the socketed package.

Socket and motherboard compatibility

The Core i7-3840QM fits Socket G2 as an FCPGA988 part at 37.5 × 37.5 mm. It also ships soldered on BGA 1224 at 31.0 × 24.0 mm, with Intel documenting both packages. The sSpec decides the board, since PGA and BGA never interchange. The BIOS must list the exact 3840QM string with late 2012 microcode.

Boards are Socket G2 quad capable designs with mobile 7 series chipsets. At 45 W a full quad heatsink with shared GPU pipes is the norm. The Socket vs chipset: what decides whether a CPU works guide covers the firmware path.

Memory, PCIe and cooling

Memory support is DDR3, DDR3L and DDR3-RS at 1333 or 1600 MT/s, two channels, up to 32 GB for 25.6 GB/s. Two matched modules feed eight threads, and the 8 MB cache reduces memory trips. ECC is not supported.

PCI Express is 16 lanes from the CPU at PCIe 3.0, split as 1x16, 2x8 or 1x8 plus 2x4. Workstation laptops devote lanes to a discrete GPU plus fast storage. Integrated graphics handle the panel on battery.

Cooling is board specific for 45 W with a 105 C junction class. High base clock makes clean airflow valuable, since sustained 2.8 GHz operation needs steady removal. Repaste during service often restores peak turbo.

Upgrade paths

On Socket G2 the Core i7-3840QM already tops the locked QM group, so same socket moves end here except for XM parts at 55 W with a power and cooling review. Memory, storage and the discrete GPU carry over where the BIOS lists the new model. The soldered twin on BGA 1224 is never an upgrade target. A slower 8 MB comparison is Intel Core i7-3820QM.

A platform change means a new mobile workstation on a newer BGA package. Keep the current quad for threaded work where 8 MB cache still helps.