Skip to main content

Stutter & Frametime

Systematic approach to diagnosing VR performance problems.

Verification Status

FieldValue
Last verified2026-01-28
HeadsetPimax Crystal Super
GPURTX 5090 (powerflux)
GPU driver580.x

Symptom Index


Consistent High Frametimes

Symptom: Frametimes consistently above target (e.g., 14ms at 90Hz target of 11.1ms)

CauseDiagnosticResolution
GPU boundGPU usage 100%Reduce render resolution or detail
CPU boundGPU < 90%, CPU thread maxedReduce physics, AI, crowd settings
VRAM exhaustionStutters after load, VRAM fullLower textures, close background apps
Thermal throttleDegradation over timeCheck temps, improve cooling

Diagnostic Steps

  1. Open Task Manager → Performance
  2. Launch VR title
  3. Observe GPU and CPU utilization
  4. If GPU 100%: GPU bound
  5. If GPU < 90% with poor performance: CPU bound or driver issue

Periodic Spikes

Symptom: Stable frametimes with intermittent spikes

CauseDiagnosticResolution
Background processSpikes correlate with app activityDisable startup apps, check scheduler
Asset streamingSpikes when entering new areasMove to SSD, adjust streaming settings
Driver overheadRandom patternTest different driver versions
USB bandwidthSpikes with tracking glitchesDifferent USB controller or port

Diagnostic Steps

  1. Note spike timing and pattern
  2. Correlate with:
    • Game events (area transitions, combat)
    • System events (notifications, updates)
    • Tracking behavior

Reprojection Artifacts

Symptom: Visual doubling, smearing, or wobble

CauseDiagnosticResolution
Forced reprojectionSmart smoothing activeReduce settings for native framerate
Tracking issuesArtifacts follow head movementCheck base station visibility
Dual smoothingBoth PiTool and SteamVR enabledDisable SteamVR Motion Smoothing

Diagnostic Tools

Built-in

  • PiTool overlay: Frametime graph, reprojection status
  • SteamVR Frame Timing: Settings → Developer → Display Frame Timing
  • fpsVR: Third-party overlay with detailed metrics

System

  • Task Manager: Per-process utilization
  • HWiNFO64: Temperature and throttling
  • LatencyMon: DPC latency analysis

Version-Specific Issues

VersionKnown IssueStatus

Revision History

DateChange
Initial document