Check Nichia 219C D260 9050 90+ CRI Emitter output test by Texas_Ace
| 1.0 A | 353 lm | 122.0 lm/W | 353 lm/A |
| 0.5 A | 198 lm | 141.8 lm/W | 396 lm/A |
| 0.25A | 111 lm | 163.2 lm/W | 444 lm/A |
| 0.15A | 72 lm | 178.8 lm/W | 480 lm/A |
If you run multiple leds the current on each one will be smaller, then it will be more efficient.