AMD Phenom X4 9850 (125W) socket: Socket AM2+
The AMD Phenom X4 9850 (125W) uses the Socket AM2+ socket. It is a 125 W quad-core Agena part at 2.5 GHz with 4x512 KB of L2 plus 2 MB of shared L3, the high-power bin of the 9850.
- Socket
- Socket AM2+
- Launched
- July 2008
- Cores and threads
- 4 and 4
- Default TDP
- 125 W
- Codename
- Agena
- Segment
- Desktop
- Family
- AMD Phenom X4
- Clocks
- 2.5 GHz
AMD Phenom X4 9850 (125W) specifications
| Cores | 4 |
|---|---|
| Threads | 4 |
| Core architecture | Agena cores on 65 nm |
| Clocks | 2.5 GHz (no turbo) |
| Cache | 4x512 KB L2 plus 2 MB shared L3 |
| Default TDP | 125 W |
| Manufacturing process | 65 nm |
| Memory support | DDR2-800 and DDR2-1066, two channels |
| HyperTransport | 2.0 GHz |
| PCI Express | PCIe Gen 2 from the board chipset |
| Integrated graphics | None (board video where fitted) |
| Multiplier | Locked |
| Package | Socket AM2+ (940 pins) |
| Core voltage | 1.20 to 1.30 V |
Motherboard and chipset compatibility
AMD Phenom X4 9850 (125W) needs a motherboard with a Socket AM2+ socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| 700 series | 790FX, 790X, 770 | 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 AM2+.
Socket AM2+ at a glance
| Type | PGA, 940 contacts |
|---|---|
| Package size | 40 × 40 mm |
| Introduced | November 2007 |
| Memory | DDR2 up to PC2-8500 (DDR2-1066), two channels |
| Cooler mounting holes | 48 × 96 mm |
What the Phenom X4 9850 (125W) is
The AMD Phenom X4 9850 (125W) is a 2.5 GHz quad core from July 1, 2008. It runs four K10 cores at 2.5 GHz with no turbo, so 4 cores give 4 threads. Cache is 512 KB of L2 per core under a shared 2 MB L3 on a 65 nm process. Power is rated at 125 W on Socket AM2+.
The 125W 9850 is built on the B3 stepping at 1.20 to 1.30 V, part HD9850XAJ4BGH, with no TLB erratum, and its HyperTransport link runs at 2.0 GHz. It exists as the high-power bin of the 9850 for boards with strong voltage regulation, which is why the TDP suffix matters when buying.
Socket and motherboard compatibility
The 9850 (125W) needs a Socket AM2+ board with DDR2 memory, robust voltage regulation and a BIOS that recognizes high-power Agena parts. Not every AM2+ board feeds 125 W quads, so the CPU support list matters. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.
Memory, PCIe and cooling
Memory is DDR2-800 and DDR2-1066 in two channels.
HyperTransport 3.0 at 2.0 GHz links the CPU to the chipset. PCIe Gen 2 slots hang off the chipset.
Cooling must be rated for 125 W on the 48 x 96 mm mount, since sustained loads hold all four cores at full speed.
Upgrade paths
On Socket AM2+ the upgrade is the AMD Phenom X4 9950 BE (125W) at 2.6 GHz unlocked, or the AMD Phenom X4 9850 (95W) where the board only feeds 95 W. The AMD Phenom X4 9850 BE is the unlocked 125 W quad for tuners.
Frequently asked questions
What socket does the Phenom X4 9850 (125W) use?
Socket AM2+, the 940-pin package on DDR2 boards, but only on boards rated for 125 W quads.
How many cores does the Phenom X4 9850 (125W) have?
Four cores and 4 threads at 2.5 GHz with 512 KB of L2 per core plus 2 MB of shared L3.
What is the difference between the Phenom X4 9850 (125W) and 9850 (95W)?
The 125W version is the high-power bin; the 95W version fits boards that cannot feed 125 W.
Sources and verification
Facts last checked against these sources on . Page last edited on .