All Site-Log / iLog data loggers come with 4 mega-byte on-board flash memory. The following table provides relationship between number of enabled channels, sampling interval and the maximum time span of logging:
| Sampling Interval | Enabled Channel | Logging Capacity |
| 1 minute | 1 | 3.98 years |
| 1 minute | 2 | 727 days |
| 1 minute | 8 | 181 days |
| 10 seconds | 1 | 242 days |
| 10 seconds | 2 | 121 days |
| 10 seconds | 8 | 30 days |
| 1 second | 1 | 24 days |
| 1 second | 2 | 12 days |
| 1 second | 8 | 3 days |
| 100 milliseconds | 1 | 58 hours |
| 100 milliseconds | 2 | 29 hours |
| 100 milliseconds | 8 | 7.2 hours |
All Precise-Log data loggers come with 8 mega-byte on board flash memory.