AMD Athlon II X4 651 socket: Socket FM1
The AMD Athlon II X4 651 uses the Socket FM1 socket. It is a 100 W quad core Llano part at 3.0 GHz without graphics for tower desktops.
- Socket
- Socket FM1
- Launched
- November 2011
- Cores and threads
- 4 and 4
- Default TDP
- 100 W
- Codename
- Llano
- Segment
- Desktop
- Family
- AMD Athlon II X4
- Clocks
- 3.0 GHz
AMD Athlon II X4 651 specifications
| Cores | 4 |
|---|---|
| Threads | 4 |
| Core architecture | Stars (K10) cores on 32 nm |
| Clocks | 3.0 GHz (no turbo) |
| Cache | 4 MB L2 (1 MB per core, no L3) |
| Default TDP | 100 W |
| Manufacturing process | 32 nm |
| Memory support | DDR3 up to 1866 MT/s, two channels |
| PCI Express | PCIe 2.0 from the CPU |
| Integrated graphics | None |
| Multiplier | Locked |
| Package | Socket FM1 (PGA, 905 contacts) |
Motherboard and chipset compatibility
AMD Athlon II X4 651 needs a motherboard with a Socket FM1 socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| Hudson FCH (A55 and A75) | A75, A55 | 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 Socket FM1.
Socket FM1 at a glance
| Type | PGA, 905 contacts |
|---|---|
| Package size | n/a |
| Introduced | June 2011 |
| Memory | DDR3-1600 and 1866, two channels |
| Cooler mounting holes | 48 × 96 mm |
What the Athlon II X4 651 is
AMD Athlon II X4 651 is a quad core Llano processor that AMD released in November 2011 for socketed desktops. It uses the Stars K10 core design on a 32 nm process, running at 3.0 GHz with no turbo. The cache is 4 MB of L2 with 1 MB per core and no L3. Power is 100 W. There are no integrated graphics on this Athlon variant, so a separate card is required.
High fixed clocks with four cores suit threaded home work that never uses turbo. The 400 MHz step over the 631 at the same power shows in both single thread and threaded tasks. Threads equal cores at 4.
Towers pair it with A55 or A75 boards, 4 GB to 8 GB of DDR3 and a discrete card. Fixed 3.0 GHz clocks keep behavior predictable. The LGA, PGA and BGA: CPU package types explained guide places this PGA desktop part against BGA mobile forms.
Socket and motherboard compatibility
The Athlon II X4 651 fits Socket FM1 on A55 and A75 boards. Late 2011 models need a BIOS new enough to list the exact X4 651 string. DDR3 modules match stock operation.
Power at 100 W needs a standard tower board with a full size cooler. The Socket vs chipset: what decides whether a CPU works guide covers AMD pairing rules.
Memory, PCIe and cooling
Memory support is DDR3 up to 1866 MT/s, two channels. Two matched modules give the rated bandwidth for four cores.
PCI Express is PCIe 2.0 from the CPU for one graphics slot with 16 lanes. A mainstream card of the era pairs without waste.
Cooling follows the 100 W rating with a tower air cooler. The shared AMD mount keeps choice wide.
Upgrade paths
On Socket FM1 the Athlon II X4 651 can move to the unlocked X4 651K on the same board for multiplier headroom. Memory, storage and the graphics card carry over. An unlocked comparison is AMD Athlon II X4 651K on the same socket.
A platform move to Socket FM2 needs a new board while DDR3 often carries over.
Frequently asked questions
What socket does the AMD Athlon II X4 651 use?
It uses Socket FM1. Boards need a BIOS new enough to list this late 2011 model.
Does the Athlon II X4 651 have integrated graphics?
No. It needs a separate graphics card for any display output.
What memory does the Athlon II X4 651 use?
DDR3 up to 1866 MT/s, two channels.
Is the Athlon II X4 651 unlocked?
No. The multiplier is locked. The X4 651K on the same socket is unlocked.
Sources and verification
Facts last checked against these sources on . Page last edited on .