Proxmox: Windows is slow with CPU type host (md_clear and flush_l1d)

host exposes md_clear and flush_l1d; Windows sees them and enables mitigations that multiply RAM latency (100 ns → 2000 ns on old Xeons). x86-64-v2-AES or v3 do not expose them. qm set –cpu and stop/start.

September 25, 2026 · 3 min