AMD Athlon II X3 455 socket: Socket AM3

What the Athlon II X3 455 is

The AMD Athlon II X3 455 is a triple core Rana desktop processor that AMD released in December 2010 for budget towers. It runs three K10 cores at a fixed 3.3 GHz with no turbo, so 3 cores give 3 threads. Each core carries 512 KB of full speed L2 cache for 1.5 MB in total, and there is no L3 cache on the die. Power is rated at 95 W on a 45 nm process with a 938-pin micro pin grid array package.

The 455 sits at the top of the Rana triple range except for the later 460. It adds 100 MHz over the 450 and 200 MHz over the 445, which shows in single threaded office work and light photo edits. Against quad Propus parts at similar clocks it trails in rendering and encoding because the fourth core is absent. Against dual core Regor parts it leads in multitasking because the third core absorbs background tasks.

There is no integrated graphics on this die. AM3 boards with 7 and 8 series chipsets provide board video where fitted, usually a basic 2D output for office displays. Memory is DDR3 in two channels through the on chip controller, with DDR2 operation possible on AM2+ boards after a BIOS update.

Socket and motherboard compatibility

The Athlon II X3 455 fits Socket AM3 with 938 pins in micro pin grid array form. All 7 series and 8 series boards boot Rana directly because the triple launched inside the AM3 era. No BIOS step is needed on boards sold from 2010 onward, while very early 2009 boards may want the latest firmware for correct temperature reporting.

AM3 chips also fit AM3+ boards, while AM3+ Bulldozer chips never fit AM3. The 455 also boots on Socket AM2+ boards with DDR2 after a BIOS update, which suits reuse of a DDR2 tower. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules, and the AMD Athlon II X3 450 page shows the 100 MHz slower sibling for comparison.

Memory, PCIe and cooling

Memory support is DDR2 up to PC2-8500 and DDR3 up to PC3-10600, in two channels through the integrated controller. A matched 2 by 2 GB DDR3-1333 kit suits most 455 towers, with 8 GB across two DIMMs as the practical ceiling on many micro ATX boards. ECC UDIMMs work only where the board wires them, which budget boards often omit.

HyperTransport 3.0 links the CPU to the chipset at 2.0 GHz. PCIe slots hang off the board chipset rather than the processor, with Gen 2 speeds from 7 and 8 series chipsets. A single x16 slot at Gen 2 carries period graphics cards without a CPU lane limit because the link is chipset side.

Cooling is the stock 95 W heatsink on the 48 × 96 mm mount shared with AM2, AM2+, AM3+ and FM2. Retail boxes shipped with a low profile aluminum sink and fan rated for 95 W. Replacement towers for this pattern remain easy to find, and a 95 W rated tower with normal case airflow keeps full load temperatures inside the 71 C class typical of Rana.

Upgrade paths

On Socket AM3 the 455 already sits near the top of the Rana triple line, so the same socket upgrade is a quad or a Phenom II with L3 cache. An Athlon II X4 645 at 3.1 GHz adds a fourth core on the same board and cooler class. A Phenom II X4 965 Black Edition at 3.4 GHz adds 6 MB of L3 cache and an unlocked multiplier for overclocking, at 125 W with stronger cooling.

A move beyond AM3 needs a new board and memory. DDR3 modules carry to AM3+ with an FX part such as the AMD Phenom II X4 975 BE class, while DDR4 or current platforms need AM4 or newer with new modules. Keep the 455 where office work dominates, and change platform where threaded rendering pays for the move.