AMD Phenom X4 9850 BE socket: Socket AM2+
The AMD Phenom X4 9850 Black Edition uses the Socket AM2+ socket. It is an unlocked 125 W quad-core Agena part at 2.5 GHz with 4x512 KB of L2 plus 2 MB of shared L3 for overclockers.
- Socket
- Socket AM2+
- Launched
- March 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 BE 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 from the board chipset |
| Integrated graphics | None (board video where fitted) |
| Multiplier | Unlocked (Black Edition) |
| Package | Socket AM2+ (940 pins) |
| Core voltage | 1.20 to 1.30 V |
Motherboard and chipset compatibility
AMD Phenom X4 9850 BE 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 BE is
The AMD Phenom X4 9850 Black Edition is an unlocked 2.5 GHz quad core from March 27, 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 9850 BE is built on the fixed B3 stepping at 1.20 to 1.30 V, part HD985ZXAJ4BGH, with no TLB erratum, and its HyperTransport link runs at 2.0 GHz. It exists because AMD gave tuners an unlocked 2.5 GHz quad early in the B3 generation, matching the locked 125W 9850 that followed in July at stock while offering multiplier headroom.
Socket and motherboard compatibility
The 9850 BE needs a Socket AM2+ board with DDR2 memory, robust voltage regulation and a BIOS that recognizes high-power Agena parts, ideally an overclocking-friendly board with voltage control. Not every AM2+ board feeds 125 W quads. 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 slots hang off the chipset.
Cooling must be a tower heatsink rated above 125 W on the 48 x 96 mm mount, since tuned voltages push heat past stock levels.
Upgrade paths
On Socket AM2+ the upgrade is the AMD Phenom X4 9950 BE (125W) at 2.6 GHz unlocked for the fastest tunable Agena. The AMD Phenom X4 9850 (125W) matches it at stock with a locked multiplier, and the AMD Phenom X3 8750 BE is the unlocked triple for cheaper tuning.
Frequently asked questions
What socket does the Phenom X4 9850 BE 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 BE have?
Four cores and 4 threads at 2.5 GHz with 512 KB of L2 per core plus 2 MB of shared L3.
Is the Phenom X4 9850 BE unlocked?
Yes, the Black Edition suffix means the multiplier is unlocked for overclocking.
Sources and verification
Facts last checked against these sources on . Page last edited on .