Sudden lag when moving fast / in populated areas, started randomly, happens on ALL servers, extensive troubleshooting done

FiveM build: 35227
GTA V version: Latest
Up to date: Yes
Legit or Pirate copy: Legit
Windows version: Windows 10 Pro
System specs: Ryzen 5 7600x, GTX 1650, 16GB DDR5 (2x8GB, running at stock 5200MT/s, EXPO not confirmed enabled), Samsung 990 Pro 2TB NVMe (1TB free)

What is the issue you’re having?
Heavy lag/stutter specifically triggered by moving fast or entering populated areas. This started randomly after previously running fine — no clear trigger identified despite thorough investigation. Happens on every server I play on, not just one.

What have you tried already?

  • Confirmed NOT thermal/power throttling (temps and clocks normal during lag)
  • Confirmed NOT VRAM/GPU related — raising graphics settings to max produces identical lag, not worse
  • Cleared FiveM cache, fully reinstalled
  • Updated GPU drivers (also tried rollback)
  • Disabled/removed all mods and resources
  • Ruled out Windows Search indexing (fully disabled, no change)
  • Checked per-core CPU usage during lag spikes — no single core maxed out, all 12 threads show moderate/even load
  • Checked disk (990 Pro NVMe) — Active Time showed 100% but Response Time stayed steady/low, consistent with known NVMe Task Manager reporting quirk, not an actual bottleneck
  • Checked network — ran continuous background ping test during lag spikes, ping stayed low/stable throughout
  • Closed all background apps (Discord, browser, etc.) before testing — no change

Current RAM observation:
RAM sits around 14/16GB (87.5%) during gameplay in populated areas. Haven’t yet tracked minute-by-minute over a full session to confirm if it’s a static ceiling or climbs over time (possible leak).

What I’m looking for:
Has anyone hit this exact pattern, fine for a long time, then suddenly laggy specifically at speed/high pop, across all servers, with GPU/CPU/disk/network/thermals all ruled out? Trying to figure out if this is a known issue with build 35227, a RAM ceiling, or something else. Happy to provide resmon/CPU-Z screenshots if allowed to run resmon on a specific server.