Intel Core 2 Duo T7600 socket: Socket M

What the Core 2 Duo T7600 is

The Intel Core 2 Duo T7600 clocks 2.33 GHz and sits at the top of the Socket M Merom range from the summer of 2006. Its two 65 nm cores share a full 4 MB pool of L2 cache with nothing deactivated, and the chip handles 64-bit code through Intel 64 next to SSSE3 instructions, an XD bit, and Enhanced SpeedStep that scales clocks and voltage with load. Two cores provide 2 threads, and 2.33 GHz holds steady under load because turbo modes did not yet exist in this generation. Intel priced the tray part at 637 dollars, which kept it in high end notebooks rather than mainstream machines.

Fourteen times the 667 MT/s front side bus gives the core speed, from a 166 MHz base clock times a multiplier of 14. The die holds 293 million transistors on 143 square mm of 65 nm silicon, and voltage ranges from 0.95 to 1.175 V under SpeedStep control. Virtualization support is present through VT-x, as it is across the full T7xxx line, and the B2 stepping covered the first shipments. Against the Core Duo T2700 it replaced at the same 2.33 GHz, the T7600 adds 64-bit support and twice the cache on the same bus, which is why Merom reads as a straight successor rather than a speed bump.

The T7600 shipped in two packages with the same silicon. The socketed Micro-FCPGA version carries part numbers starting in LF, with sSpec SL9SD, and drops into the Socket M lever socket. The soldered FCBGA6 twin carries numbers starting in LE, with sSpec SL9SJ, and is fixed to the board at the factory. Where a SKU exists in both a socketed and a soldered package this site lists it under the socketed package, so this page covers the LF socketed part and notes the LE twin for completeness.

Socket and motherboard compatibility

Socket M, printed mPGA478MT, is a 478-contact PGA-ZIF socket introduced in 2006 for the Napa platform. The natural board partners are the Mobile Intel 945PM and 945GM chipsets, which support the 667 MT/s bus this chip needs, with select PM965 and GM965 boards offering 800 MT/s combinations that remain less common on this socket. Each board needs a BIOS revision that lists the exact sSpec stepping, since Napa BIOS releases added Merom support after launch and an early BIOS may not recognize the chip.

Socket M is not interchangeable with its neighbours. It is pin compatible with older mobile Socket 479 in the mechanical sense but not electrically compatible, it does not fit desktop Socket 478, and it differs from Socket P by the location of one pin, so a later 800 MT/s Santa Rosa chip will not seat correctly. Boards built for the soldered FCBGA6 twin accept no socketed upgrade at all. Before buying a used T7600, confirm the notebook vendor CPU support list names SL9SD, because some Napa boards never received a Merom BIOS.

Memory, PCIe and cooling

Memory on a T7600 system is DDR2 in two channels through the board chipset, commonly DDR2-667 SO-DIMMs on 945PM and 945GM boards. The processor has no memory controller of its own, so the chipset sets the speed, the slot count, and the maximum capacity. The board vendor list fixes those limits, and a move to DDR3 means a move to a newer mobile platform with a new board.

No PCI Express lanes come from the CPU itself. A 667 MT/s front side bus ties the chip to the mobile chipset, while graphics and expansion slots hang off the chipset. Cooling uses notebook vendor heat pipe assemblies built for the exact chassis, since retail desktop towers do not mount to mobile sockets. Paste or pad replacement follows the notebook service manual for the exact model.

Power deserves a note because two references differ by one watt. The mobile processor list, the boxed retail part BX80537T7600, and every sibling Merom on Socket M record 34 W, while the TechPowerUp page for the T7600 records 35 W. This page uses 34 W with the whole range and calls out the single differing entry so a reader comparing sources is not surprised.

Upgrade paths

On Socket M there is no step up from a T7600, since 2.33 GHz with the full 4 MB cache is the fastest Merom Intel offered for this socket. A machine that already holds one keeps it. A machine holding a smaller cache part such as the Intel Core 2 Duo T5600 can move to the T7600 for more cache and clocks on the same bus and power budget, provided the BIOS lists SL9SD. The Intel Core 2 Duo T7400 at 2.17 GHz is the closest alternative when a T7600 is hard to find used.

A move past 2.33 GHz means leaving Socket M. The successor Socket P arrived in 2007 with an 800 MT/s bus for Santa Rosa, carrying Merom parts such as the 2.2 GHz T7500 and later 45 nm Penryn chips, and every one of those needs its own board. The soldered FCBGA6 twin offers no CPU upgrade path at all, since the chip cannot be removed; a faster machine then means replacing the whole board or notebook.