High Pressure Sodium (HPS) light sources feature highly energy efficient performance with very long life by comparison to other conventional lamps. High pressure sodium lamps last longer than metal halide and produce more lumens per watt, however they are easily recognized by their amber color output and poor color rendering. Efficacy and uniformity of HPS is generally lower than LED alternatives. HPS does not provide "instant-on" capability so 10-15 minutes of additional time is required for startup or restrike. Dimming is not practical, so intelligent controls options are limited to on/off and monitoring. HPS sources generally last from 12,000 to 24,000 hours.