Question
Low Interpolation Delay vs. High Snapshot Buffer for Jitter Tolerance
Ash Echo
0 reputation · 29 Dec 2022, 18:07 UTC
107.2K views1
Loading…
0 reputation · 29 Dec 2022, 18:07 UTC
In the original Source Engine networking model, clients render remote entities in the past to ensure smooth movement via interpolation. This process relies on the cl_interp and cl_interp_ratio variables to determine how many snapshots are buffered before rendering.
A primary design conflict arises when balancing the perceived responsiveness of hit registration against the stability of entity movement under suboptimal network conditions. Minimizing the interpolation buffer reduces the time difference between the client's view and the server's current state, which mitigates the "shot behind cover" effect for victims. However, this leaves the client with a smaller safety margin to handle packet jitter or loss.
Conversely, increasing the interpolation ratio provides a smoother experience for players with unstable connections but increases the effective latency that the server's lag compensation system must rewind during hitscan calculations.
Given these constraints, what is the optimal balance for sv_client_min_interp_ratio on a high-tickrate server to prevent stuttering without introducing excessive lag compensation windows? Under what specific network jitter thresholds does the benefit of a higher interpolation buffer outweigh the cost of increased effective latency?
For a high-tickrate (100 tick) Source server with a mixed player population, set sv_client_min_interp_ratio 1 and recommend clients use cl_interp_ratio 2 (which yields a 20 ms lerp at 100 tick). This gives stable connections the option to manually drop to ratio 1 (10 ms lerp) via autoexec, while providing a one-tick jitter buffer for the majority.
sourceenginelerp + ping ≈ 20 ms + ping, which is generally acceptable for competitive play.| Interpolation Ratio | Lerp Time | Jitter Tolerance (approx.) | Rewind Window Increase |
|---|---|---|---|
| 1 | 10 ms | < 5 ms (50% of tick interval) | Baseline |
| 2 | 20 ms | 5–10 ms | +10 ms |
| 3 | 30 ms | 10–20 ms | +20 ms |
If your player base regularly experiences jitter above 10 ms, ratio 2 is the practical ceiling; beyond that, connection quality issues should be addressed at the network level rather than by inflating the interpolation buffer.
sv_maxupdaterate 100
sv_minupdaterate 100
sv_client_min_interp_ratio 1net_graph 1 and observe the lerp value and color:
tc qdisc add dev eth0 root netem delay 30ms 8ms distribution normalversioncl_updaterate matches server tickrate (100). Clients forcing lower updaterates artificially inflate lerp regardless of ratio.sv_client_min_interp_ratio only clamps the minimum; clients can still use higher ratios. Enforcing an exact ratio requires a plugin.sv_maxunlag (default 0.2 s), which may truncate high-ratio compensation for high-ping players.What is the exact server tickrate (66 or 100) and the typical ping/jitter distribution of your player base? The 50% tick-interval threshold changes from 5 ms (100 tick) to 7.5 ms (66 tick), and the optimal default ratio may shift if most players sit on 60+ ms ping with >10 ms jitter.
Use comments to ask for clarification. Post a solution as an answer.
No question comments on this page.