Socket G1 socket: CPUs, chipsets and cooler fit
Socket G1, also called rPGA988A, is the Intel socket for the first generation of Core mobile processors. It carries 988 pins in a reduced pitch grid array and takes 37.5 by 37.5 mm packages. Intel introduced it in September 2009 with Clarksfield quad parts, then added Arrandale dual parts with on-package Ironlake graphics in January 2010. Calpella platform boards with HM55, HM57 and QM57 chipsets carry it.
Quick facts
| Maker | Intel |
|---|---|
| Package type | rPGA |
| Contacts | 988 |
| Package size | n/a |
| Introduced | September 2009 |
| Status | Legacy |
| Memory | DDR3, two channels, up to 8 GB |
| PCIe from the CPU | PCIe 2.0, 16 lanes |
| Cooler mounting holes | Board specific (laptop heatsink) |
| Replaces | Socket P |
| Replaced by | Socket G2 |
Overview
The socket covers two very different dies. Arrandale duals pair a 32 nm CPU die with a 45 nm graphics and memory controller die on the same package, which brought graphics onto the mobile processor for the first time in this line. Clarksfield quads use a single 45 nm die with no graphics block, so those laptops always include a separate GPU. Both groups share the same 988 pin socket but never share boards with the later Socket G2, even though the pin count matches.
Do not confuse Socket G1 with Socket G2. G1 is rPGA988A for Arrandale and Clarksfield, while G2 is rPGA988B for Sandy and Ivy Bridge. The key pin sits in a different place, the electrical layout differs, and the BIOS generations never cross. Later Intel mobile parts moved to Socket G2 in 2011 and then to soldered BGA packages.
Processor generations
| Codename | Marketing name | Years | Notes |
|---|---|---|---|
| Arrandale | 1st Gen Core mobile M and UM | 2010 to 2011 | Socketed Arrandale dual core mobile from Celeron P4000 through Pentium P6000 and Core i3, i5 and i7 M parts at 35 W, plus 18 W ULV, launched in January 2010 with Ironlake graphics. |
| Clarksfield | 1st Gen Core mobile QM and XM | 2009 to 2010 | Socketed Clarksfield quad core mobile including the i7-720QM, 820QM and 920XM at 45 W to 55 W with no on-package graphics, launched in September 2009. |
Chipsets for Socket G1
5 series mobile
Calpella platform chipsets for Arrandale laptops, launched in 2010.
| Chipset | Segment | Notes |
|---|---|---|
| HM55 | Mainstream | |
| HM57 | High-end | |
| QM57 | Business |
Socketed mobile package
Socket G1 processors drop into a 988 pin grid with a cam actuated retention mechanism. The chip carries the pins and the socket provides the holes, which is the reverse of desktop LGA designs. Upgrades stay within the same generation and power class, and the board BIOS must list the exact model string.
In practice compatibility depends on the chipset and the BIOS age. HM55, HM57 and QM57 boards from the Calpella platform carry Arrandale duals, while Clarksfield quads need boards wired for 45 W to 55 W with discrete graphics. A board that lists the exact model is the safe choice, and used laptops should be checked as whole systems rather than CPU donors.
Memory and I/O
Socket G1 designs use DDR3 SODIMMs in two channels, commonly at 800 or 1066 MT/s for up to 8 GB. Two matched modules give the rated bandwidth, which feeds both the cores and the Ironlake graphics block that shares system RAM. Many Arrandale laptops shipped a single module, so adding a matched second module is a cheap improvement.
PCI Express is revision 2.0 with 16 lanes from the package for discrete graphics and I/O. Arrandale laptops with switchable graphics spend lanes on a separate GPU alongside the on-package block. Cooling stays board specific with laptop heat pipes and fans, and the CPU cooler compatibility by socket guide explains why no retail desktop mount fits.
Platform lifecycle
Socket G1 belongs to the 2009 to 2011 mobile generation. Intel moved performance mobile to Socket G2 for Sandy Bridge in 2011 with a new key pin and DDR3-1600 support. No new Socket G1 parts followed, so boards and chips are used or old stock.
For a working Socket G1 laptop the useful work is maintenance: clean fans, renew paste where the design allows service, and fit an SSD and enough RAM. A platform move means a new laptop on a current package. The How to find your CPU socket type guide shows how to confirm the socket before ordering parts.
CPUs on Socket G1
25 processor pages in the database, newest first.
| Processor | Cores / threads | Base / boost | TDP | Launched |
|---|---|---|---|---|
| Intel Core i3-390M | 2 / 4 | 2.67 GHz | 35 W | Jan 2011 |
| Intel Core i5-480M | 2 / 4 | 2.67 / 2.93 GHz | 35 W | Jan 2011 |
| Intel Pentium P6300 | 2 / 2 | 2.27 GHz | 35 W | Jan 2011 |
| Intel Core i3-380M | 2 / 4 | 2.53 GHz | 35 W | Oct 2010 |
| Intel Core i5-460M | 2 / 4 | 2.53 / 2.8 GHz | 35 W | Sep 2010 |
| Intel Core i5-560M | 2 / 4 | 2.67 / 3.2 GHz | 35 W | Sep 2010 |
| Intel Core i5-580M | 2 / 4 | 2.67 / 3.33 GHz | 35 W | Sep 2010 |
| Intel Core i7-640M | 2 / 4 | 2.8 / 3.47 GHz | 35 W | Sep 2010 |
| Intel Pentium P6100 | 2 / 2 | 2.0 GHz | 35 W | Sep 2010 |
| Intel Pentium P6200 | 2 / 2 | 2.13 GHz | 35 W | Sep 2010 |
| Intel Core i7-840QM | 4 / 8 | 1.87 / 3.2 GHz | 45 W | Jun 2010 |
| Intel Core i3-370M | 2 / 4 | 2.4 GHz | 35 W | Jun 2010 |
| Intel Core i5-450M | 2 / 4 | 2.4 / 2.67 GHz | 35 W | Jun 2010 |
| Intel Core i7-740QM | 4 / 8 | 1.73 / 2.93 GHz | 45 W | Jun 2010 |
| Intel Core i7-940XM | 4 / 8 | 2.13 / 3.33 GHz | 55 W | Jun 2010 |
| Intel Pentium P6000 | 2 / 2 | 1.88 GHz | 35 W | Jun 2010 |
| Intel Core i3-330M | 2 / 4 | 2.13 GHz | 35 W | Jan 2010 |
| Intel Core i3-350M | 2 / 4 | 2.27 GHz | 35 W | Jan 2010 |
| Intel Core i5-430M | 2 / 4 | 2.27 / 2.53 GHz | 35 W | Jan 2010 |
| Intel Core i5-520M | 2 / 4 | 2.4 / 2.93 GHz | 35 W | Jan 2010 |
| Intel Core i5-540M | 2 / 4 | 2.53 / 3.06 GHz | 35 W | Jan 2010 |
| Intel Core i7-620M | 2 / 4 | 2.68 / 3.33 GHz | 35 W | Jan 2010 |
| Intel Core i7-920XM | 4 / 8 | 2.0 / 3.2 GHz | 55 W | Sep 2009 |
| Intel Core i7-720QM | 4 / 8 | 1.6 / 2.8 GHz | 45 W | Sep 2009 |
| Intel Core i7-820QM | 4 / 8 | 1.73 / 3.07 GHz | 45 W | Sep 2009 |
Frequently asked questions
Which processors fit Socket G1?
Arrandale dual core M parts such as the Core i3-390M and Pentium P6300, plus Clarksfield quad parts such as the i7-720QM. Soldered BGA1288 versions of some ULV SKUs use BGA 1288 instead.
Is Socket G1 the same as Socket G2?
No. Socket G1 is rPGA988A for Arrandale and Clarksfield mobile. Socket G2 is rPGA988B for Sandy and Ivy Bridge mobile. Parts do not move between them, and the key pin differs.
What memory does Socket G1 use?
DDR3 SODIMMs in two channels, commonly 800 to 1066 MT/s on Arrandale and up to 1333 MT/s on some boards, up to 8 GB. Two matched modules help the Ironlake graphics block.
Can Socket G1 overclock?
Yes, on Extreme XM processors such as the i7-940XM where the board firmware allows it. Locked M parts run at rated speeds.
Sources and verification
- Socket G1 (Wikipedia, rPGA988A, 988 contacts, Arrandale)
- Arrandale (Wikipedia, rPGA-988 and BGA-1288, DDR3, Jan 2010)
- Intel Core i3-390M Specs (TechPowerUp, Arrandale, Socket G1, Jan 2011)
Facts last checked against these sources on . Page last edited on .