Well, from the Steam Deck tech specs page:

Processor

6 nm AMD APU

CPU: Zen 2 4c/8t, 2.4-3.5GHz (up to 448 GFlops FP32)

GPU: 8 RDNA 2 CUs, 1.6GHz (1.6 TFlops FP32) APU power: 4-15W

RAM 16 GB LPDDR5 on-board RAM (6400 MT/s quad 32-bit channels)

Then what we know about the Steam Machine, also from the tech specs page:

CPU Semi-custom AMD Zen 4 6C / 12T up to 4.8 GHz, 30W TDP

GPU Semi-Custom AMD RDNA3 28CUs 2.45GHz max sustained clock, 110W TDP

RAM 16GB DDR5 + 8GB GDDR6 VRAM