Phase A.5's two-tier streaming spec promised that far-tier landblocks
ship terrain ONLY — no entities, no scenery, no interior cells. T13/T16
wired the controller side (RecenterTo emits ToLoadFar/ToLoadNear/ToPromote;
controller passes JobKind to the worker), but the worker's HandleJob
never branched on Kind: every load called BuildLandblockForStreaming
which runs the full hydration + scenery generation + interior cell path.
Result: at default radii (N₁=4 / N₂=12), 540 far-tier LBs each loaded
their full entity layer (~132 entities/LB → ~71K entities total) into
GpuWorldState. The dispatcher then walked all ~54K entities per frame
(post-frustum-cull), driving the entity dispatcher cpu_us from ~3.6ms
median (T24 baseline) to ~18-21ms (post-T22.5 horizon-test). User-
observed: 40 FPS / 25ms frame time at horizon-safe settings; system
crash at full High preset.
Minimum-diff fix: in LandblockStreamer.HandleJob, after
_loadLandblock returns, strip Entities to empty for LoadFar before
posting Loaded. Worker still does wasted hydration CPU (off the render
thread, harmless). Render-side dispatcher walk drops from ~54K to ~10K
entities/frame.
Math: post-fix entity dispatcher should drop to ~3-4ms median at N₁=4 /
N₂=12 (matches T24's 3.6ms at radius=5 single-tier, since N₁=4 has 33%
fewer near entities than N₁=5).
Future optimization (N.6 / A.6): plumb JobKind through
BuildLandblockForStreaming so the worker also skips the wasted CPU.
Out of A.5 scope.
Bug B (T17 WalkEntities allocation) is a smaller perf hit — defer if
post-Bug-A FPS is acceptable.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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