Question about Corsair H80i v2

Rather less... To cool the processor properly in all situations, I would either use a powerful air cooler or a 280/360 Wakü:

Air:
Noctua NH-D15 (16.50cm)
be quiet! Dark Rock Pro 4 (16.28cm)

Water:
280:
Corsair H115i Pro
NZXT Kraken x62 incl. AM4 (3cm)
360:
Corsair H150i Pro
NZXT Kraken X72