Why Steam Deck (LCD & OLED) stutters (or pages)
Deck hitching in Elden Ring, Cyberpunk, or modded Skyrim usually looks like GPU stutter but is often UMA relocation: textures spill from a tiny fixed framebuffer into system RAM while zram and the swapfile fight for the same 16GB pool. OLED’s faster LPDDR5-6400 helps bandwidth, not capacity — once SteamOS, Proton, and the game’s working set exceed ~12GB, you feel multi-frame freezes on zone loads.
What to buy or configure
Buy Deck capacity at the hardware SKU (always 16GB). Spend upgrade budget on a fast NVMe and a tuned swap profile, not “RAM upgrades.” If you need socketed dual-channel SO-DIMMs for desktop-class multitasking, jump to a Beelink/Minisforum mini-PC guide instead.
Memory deep dive
Valve’s Steam Deck pairs a custom AMD APU with 16GB of soldered LPDDR5 (LCD ~5500 MT/s, OLED ~6400 MT/s) on a wide bus. Physical module upgrades are impossible without BGA rework that bricks most units. The useful “upgrade path” is software: BIOS UMA sizing, swap policy, and Proton/shader cache hygiene so the fixed 16GB pool is not thrashed by Windows-like background bloat (Deck avoids that better than Ally/Legion Go, but mod stacks still punish it).
Clearance / form factor: Not applicable — LPDDR5 packages are soldered beside the APU; there are no SO-DIMM slots or heatsink clearance limits.
Tuning notes: SteamOS shares one pool between GPU and CPU. Raise BIOS UMA Frame Buffer Size from 1G to 4G so heavy titles reserve VRAM early instead of relocating mid-load. In Desktop Mode, CryoUtilities “Recommended Settings” grow the swapfile (~16GB) and enable huge pages so Proton paging is less catastrophic when AAA maps stream.