Heat sinks increases a portal‘s hack speed, meaning it reduces the cooldown time after a hack. They also reset the portal’s cooldown and burnout timers for the deploying agent at the time it is installed. The cooldown reduction of each heat sink is as follows:
- Common: -20%
- Rare: -50%
- Very Rare: -70%
If you have more than one heat sink installed on a portal, only the rarest one will function at full effectiveness; the remaining ones will be half as effective as they would normally be. The chart below shows the resulting cooldown time from every possible combination of installed heat sinks:
| Mod 1 | Mod 2 | Mod 3 | Mod 4 | Cooldown (sec) |
|---|---|---|---|---|
| 300 | ||||
| Common | 240 | |||
| Common | Common | 216 | ||
| Common | Common | Common | 194 | |
| Common | Common | Common | Common | 175 |
| Rare | 150 | |||
| Rare | Common | 135 | ||
| Rare | Common | Common | 122 | |
| Rare | Common | Common | Common | 109 |
| Rare | Rare | 113 | ||
| Rare | Rare | Common | 101 | |
| Rare | Rare | Common | Common | 91 |
| Rare | Rare | Rare | 84 | |
| Rare | Rare | Rare | Common | 76 |
| Rare | Rare | Rare | Rare | 63 |
| Very Rare | 90 | |||
| Very Rare | Common | 81 | ||
| Very Rare | Common | Common | 73 | |
| Very Rare | Common | Common | Common | 66 |
| Very Rare | Rare | 68 | ||
| Very Rare | Rare | Common | 61 | |
| Very Rare | Rare | Common | Common | 55 |
| Very Rare | Rare | Rare | 51 | |
| Very Rare | Rare | Rare | Common | 46 |
| Very Rare | Rare | Rare | Rare | 38 |
| Very Rare | Very Rare | 59 | ||
| Very Rare | Very Rare | Common | 53 | |
| Very Rare | Very Rare | Common | Common | 47 |
| Very Rare | Very Rare | Rare | 44 | |
| Very Rare | Very Rare | Rare | Common | 39 |
| Very Rare | Very Rare | Rare | Rare | 33 |
| Very Rare | Very Rare | Very Rare | 38 | |
| Very Rare | Very Rare | Very Rare | Common | 34 |
| Very Rare | Very Rare | Very Rare | Rare | 29 |
| Very Rare | Very Rare | Very Rare | Very Rare | 25 |