AMD Athlon 1266 socket: Socket 462
The AMD Athlon 1266 uses the Socket 462 socket. It is a Thunderbird desktop part at 1266 MHz with 256 KB of L2 cache for Socket 462 boards with a 266 MT/s bus.
- Socket
- Socket 462
- Launched
- March 2001
- Cores and threads
- 1 and 1
- Default TDP
- n/a
- Codename
- Thunderbird
- Segment
- Desktop
- Family
- AMD Athlon
- Clocks
- 1.27 GHz
AMD Athlon 1266 specifications
| Cores | 1 |
|---|---|
| Threads | 1 |
| Core architecture | Thunderbird cores on 180 nm |
| Clocks | 1266 MHz (no turbo) |
| Cache | 256 KB L2 |
| Manufacturing process | 180 nm |
| Memory support | DDR through the board chipset |
| Front side bus | 266 MT/s |
| PCI Express | AGP or PCI from the board chipset |
| Integrated graphics | None (board graphics where fitted) |
| Multiplier | Locked (9.5x) |
| Package | Socket 462 (462-pin OPGA) |
Motherboard compatibility
AMD Athlon 1266 needs a motherboard with a Socket 462 socket. Chipset by chipset data for this codename is not recorded yet. See the Socket 462 chipset list and the board maker's CPU support list.
Socket 462 at a glance
| Type | PGA, 462 contacts |
|---|---|
| Package size | 49.53 × 49.53 mm |
| Introduced | June 2000 |
| Memory | DDR through the board chipset, single channel |
| Cooler mounting holes | Socket lug (clip) |
What the Athlon 1266 is
The AMD Athlon 1266 is a 1266 MHz single-core desktop processor from March 2001. It runs one K7 Thunderbird core at 1266 MHz with no turbo, so 1 core gives 1 thread. Cache is 256 KB of full-speed L2 on a 180 nm process. The package is Socket 462 with part number A1266AMS3C on a 266 MT/s front side bus with a 9.5x multiplier. This page omits a TDP rating because the table gives no power figure for the 1266, while the cpu_list 66 W lacks direct table support for this exact bin.
The 1266 was a short-lived 266 MT/s Thunderbird with an odd 9.5x multiplier, placed in March 2001 between 1200 MHz and 1333 MHz parts. AMD aimed it at DDR boards with 266 MT/s chipsets that needed a mid range option. The chip supports MMX and Enhanced 3DNow.
Odd multipliers with a fast bus mark the transition from 200 MT/s to 266 MT/s Thunderbird parts. The 9.5x setting needs a BIOS that lists the 1266 explicitly, since older boards may miss half multipliers. That is why maker lists matter more than socket type for this rating.
Socket and motherboard compatibility
The Athlon 1266 fits Socket 462 desktops with a 266 MT/s bus and Thunderbird support. It needs 266 MT/s chipset paths and 9.5x multiplier support. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.
DDR towers with 266 MT/s chipsets are the natural match. Boards listing Thunderbird 1266 accept the chip with a standard Thunderbird cooler.
Memory, PCIe and cooling
Memory is DDR through the board chipset, matched to the 266 MT/s bus. The CPU has no controller.
A 266 MT/s bus ties the CPU to the chipset, while AGP and PCI hang off the chipset. No PCIe lanes originate on the die. Cooling uses the socket lug clip with a Thunderbird-rated heatsink.
Upgrade paths
On Socket 462 the steps are Thunderbird 1333 and 1400C parts on the same bus. Palomino Athlon XP parts offer lower voltage successors. Beyond Socket 462 a move to Socket 754 needs a new board. The 1266 lifts with the lever, so swaps need no solder work.
Frequently asked questions
What socket does the Athlon 1266 use?
Socket 462, on DDR desktops with a 266 MT/s bus and Thunderbird support.
How many cores does the Athlon 1266 have?
One core and 1 thread at 1266 MHz with 256 KB of L2 cache.
What memory works with the Athlon 1266?
DDR through the board chipset, matched to the 266 MT/s bus.
Can the Athlon 1266 be upgraded?
The 1333 and 1400C share the bus and socket. Palomino parts offer lower voltage successors.
Sources and verification
Facts last checked against these sources on . Page last edited on .