Intel Pentium G840 socket: LGA 1155
The Intel Pentium G840 uses the LGA 1155 socket. It is a 65 W dual core Sandy Bridge desktop part at 2.8 GHz for budget office towers.
- Socket
- LGA 1155
- Launched
- May 2011
- Cores and threads
- 2 and 2
- Base power
- 65 W
- Codename
- Sandy Bridge
- Segment
- Desktop
- Family
- Intel Pentium
- Clocks
- 2.8 GHz
Intel Pentium G840 specifications
| Cores | 2 |
|---|---|
| Threads | 2 |
| Core architecture | Sandy Bridge cores on 32 nm |
| Clocks | 2.8 GHz (no turbo) |
| Cache | 3 MB Intel Smart Cache (L3) |
| Processor base power (TDP) | 65 W |
| Manufacturing process | 32 nm |
| Memory support | DDR3-1066 and 1333, two channels, up to 32 GB |
| PCI Express | 16 lanes from the CPU, PCIe 2.0 |
| Integrated graphics | Intel HD Graphics (850 MHz to 1100 MHz) |
| Multiplier | Locked |
| Package | FCLGA1155 (37.5 × 37.5 mm) |
Motherboard and chipset compatibility
Intel Pentium G840 needs a motherboard with a LGA 1155 socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| 7 series | Z77, Z75, H77, B75, Q77, Q75 | Works out of the box |
| 6 series: H61, H67, P67, Z68 | Z68, P67, H67, H61 | Works out of the box |
| 6 series business: B65, Q65, Q67 | Q67, Q65, B65 | Works out of the box |
Board makers publish a CPU support list for every model. Check it for your exact board before buying. Chipset details for LGA 1155.
LGA 1155 at a glance
| Type | LGA, 1,155 contacts |
|---|---|
| Package size | 37.5 × 37.5 mm |
| Introduced | January 2011 |
| Memory | DDR3 |
| Cooler mounting holes | 75 × 75 mm |
What the Pentium G840 is
Intel Pentium G840 is a dual core Sandy Bridge desktop processor that Intel released in May 2011 for budget towers. It runs at a fixed 2.8 GHz with no turbo and no Hyper-Threading, so 2 cores give 2 threads. Cache is 3 MB Intel Smart Cache. Power is 65 W on a 32 nm process with a 131 mm2 die.
The G840 led the early Pentium Sandy range on clocks. Office apps open promptly and 1080p video plays through the integrated block. It still trails Core i3 parts in threaded work because Hyper-Threading is absent.
Graphics are Intel HD Graphics for Sandy Bridge at 850 MHz to 1100 MHz. The block supports two displays through board outputs. The LGA, PGA and BGA: CPU package types explained guide contrasts this desktop LGA part with soldered mobile chips.
Socket and motherboard compatibility
The Pentium G840 fits LGA 1155 in FCLGA1155 form. All 6 series boards from the Sandy launch boot it, including B65, H61, H67, P67 and Z68. Later 7 series boards accept it as well.
Memory and board choice matter more than chipset branding at this level. Any board that lists the G840 runs it at rated clocks. The Socket vs chipset: what decides whether a CPU works guide explains the support list habit.
Memory, PCIe and cooling
Memory support is DDR3-800, 1066 and 1333, two channels, up to 32 GB. Dual channel mode gives up to 21.3 GB/s with DDR3-1333. ECC is not supported.
PCI Express is 16 lanes from the CPU at PCIe 2.0. Most G840 towers keep the slot empty and use onboard video.
Cooling is the stock 65 W push pin unit on 75 × 75 mm spacing. A clean fan holds the fixed 2.8 GHz behavior.
Upgrade paths
On LGA 1155 the G840 can move to the G850 or G860 for 100 to 200 MHz more, or to a Core i3 2100 for Hyper-Threading. DDR3 and storage move with the board. A same socket Pentium reference at lower clocks is the G620 class.
A jump to DDR4 platforms needs a new board and RAM. Keep the G840 tower for school or shop use.
Frequently asked questions
What socket does the Intel Pentium G840 use?
It uses LGA 1155. All 6 series and 7 series boards boot it directly.
How is the Pentium G840 different from the G620?
The G840 runs at 2.8 GHz. The G620 runs at 2.6 GHz. Cache and power match.
What memory does the Pentium G840 use?
DDR3-1066 and 1333, two channels, up to 32 GB.
Is the Pentium G840 unlocked?
No. The multiplier is locked.
Sources and verification
- Intel Pentium G840 Specs (TechPowerUp, 2.8 GHz, 65 W, May 2011)
- Intel Pentium G840 (CPU Grade, 2.8 GHz, 3 MB, LGA1155, DDR3, 32 GB)
Facts last checked against these sources on . Page last edited on .