Why Phi 4 pressures system RAM
Phi 4 is a dense 14B network — every weight participates each token, so quantization choice dominates. Q4_K_M lands near ~7.9GB weights, plus ~0.03GB KV at 8K and ~6GB overhead (~13.9GB → 16GB kit). The 16K-token context ceiling is the sleeper cost: long-doc or agent traces inflate KV while the 14B slab stays fixed. Prefer dual-channel DDR5 bandwidth when CPU offload or mmap is involved.
What RAM kit to buy
A 16GB dual-channel kit is enough for quantized Phi 4 at modest context. Still prefer 2× matched SO-DIMM/UDIMM sticks; 1x RTX 4060 Ti (16GB VRAM) or RTX 4070 (12GB VRAM) covers the Budget / Entry GPU GPU profile. If you chat with long pastes, jump a tier before the KV cache forces paging.
Workload notes
Microsoft/Phi-class models like Phi 4 target efficient local assistants — do not overspend on 256GB+ kits unless you stack multiple sessions. At 14B, Phi 4 is compact enough for laptops and mini-PCs when quantized; dual-channel memory still matters for 1% token latency. Release window noted as 2025/2026; always re-check the model card before buying hardware for a specific checkpoint.