AMD Steam Deck CPU (LCD) socket: BGA ST1

What the Steam Deck CPU (LCD) is

The AMD Steam Deck CPU (LCD) is the 4-core Aerith APU for the original Steam Deck handheld from February 2022. Four Zen 2 cores with simultaneous multithreading give 4 cores and 8 threads, with base at 2.4 GHz and up to 3.5 GHz boost. The die carries 2 MB of L2 plus 4 MB of L3. The 15 W envelope with a 4 to 15 W configurable window fits fan cooled handheld designs, and the RDNA 2 iGPU drives the internal display without a discrete card.

AMD built the part as Van Gogh with 8 RDNA 2 compute units up to 1.6 GHz for 1.6 TFLOPS, paired with 16 GB of LPDDR5-5500 across quad 32-bit channels. The package is soldered to the handheld board, so the processor cannot be swapped later. System memory is fixed at purchase with no slots.

Handheld gamers land here for the original LCD Deck with a 7 nm Aerith APU, while the later OLED Deck moves the same architecture to a 6 nm Sephiroth shrink. The AMD Steam Deck CPU (OLED) page covers the OLED counterpart with LPDDR5-6400. The Socket vs chipset: what decides whether a CPU works guide covers board choice for soldered designs in general.

Socket and motherboard compatibility

The Aerith chip is soldered to BGA ST1 boards and cannot be replaced. There is no socket upgrade path, so buyers choose the storage size at purchase since the APU is fixed. Boards must carry the exact Van Gogh firmware for the LCD panel and controls.

Chipset functions sit in the APU itself on BGA ST1 designs, so board choice decides ports, display outputs and power delivery rather than CPU fit. The OLED Deck board is a separate design around the Sephiroth shrink, not a drop-in swap for LCD boards.

Memory, PCIe and cooling

Sixteen GB of LPDDR5-5500 in quad 32-bit channels feeds the cores and the RDNA 2 graphics together, since the graphics share system memory. The fixed 128-bit bus sets bandwidth for the 1.6 TFLOPS iGPU.

Eight Gen3 lanes on Deck designs wire NVMe storage and expansion. The Radeon 8CU RDNA 2 graphics up to 1.6 GHz cover handheld gaming without a discrete card.

Cooling is a 15 W handheld thermal design with a single fan and heat pipe for the APU. There is no retail mounting pattern, so service parts follow the handheld maker manual. Sustained clocks depend on the configured power window between 4 and 15 W.

Upgrade paths

There is no CPU upgrade path on BGA ST1 because the chip is soldered. The practical upgrades are a larger NVMe drive and a newer handheld when the platform ages. Memory is fixed at 16 GB with no slots.

Outside this APU, AMD Steam Deck CPU (OLED) on BGA ST1 moves the same architecture to the 6 nm shrink with faster memory. A move to a socketed desktop needs a new board with its own memory, so handheld replacement rather than CPU replacement is the path.