Alphacool Eisbaer Pro Aurora 280 vs NZXT Kraken Elite 280 RGBcomputed

Both coolers at the same heat load: what each dissipates, the coolant temperature over fan speed, and the fan speed and noise each needs for the same temperature. Calculated from radiator size, core thickness and the stock fans' datasheets, not measured.

Side by side

Alphacool Eisbaer Pro Aurora 280NZXT Kraken Elite 280 RGB
Radiator280 mm280 mm
Core thickness30 mm27 mm
Stock fans2 × Aurora Rise Fan1 × F280 RGB Core Fan
Fan rpm, datasheet? – 2000500 – 2000
Pump2600 rpm max2800 rpm max
Tubing400 mm400 mm
Dissipation at max rpm26.5 W/K26.0 W/K
Coolant, 250 W, 30 °C intake39.4 °C39.6 °C
Noise at max rpm, all fans–34.5 dB(A)

Coolant above intake at 250 W

0 5 10 15 20 25 0 20 40 60 80 100 % of max fan rpm Kraken Elite 280 RGB Eisbaer Pro Aurora 280 K coolant above intake, 250 W

Noise, all stock fans

No noise rating for one of the stock fans in the data.

At the same coolant temperature, 250 W

K above intakeEisbaer Pro Aurora 280 rpmdB(A)Kraken Elite 280 RGB rpmdB(A)Quieter
10.01815–186933.0
12.51251–128925.0
15.0923–95118.6
17.5714–735<15
20.0572–589<15
25.0394–500 min<15

The Eisbaer Pro Aurora 280 dissipates 26.5 W/K against 26.0 W/K at max fan rpm. No noise rating for one of the stock fans in the data yet, so temperature only. A cooler pinned at its fan's minimum rpm runs colder than the row asks; the comparison is then not at equal temperature.

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How these numbers are computed

A radiator moves heat in proportion to the difference between coolant and incoming air: Q = q · (Tcoolant − Tair). q depends on the air actually passing through the core. Airflow per fan is CFMmax · derate · rpm/rpmmax with the radiator derate (0.62, or 0.72 for pressure-optimized blades) times the core-thickness factor. Per 120 mm segment at 27 mm: q = 8.5 W/K · (airflow / 45 CFM)0.6; heat transfer over fins scales with roughly the 0.6 power of velocity.

CoreAirflow factorFin area factor
27 mm1.001.00
30 mm0.971.09
38 mm0.901.15
45 mm0.841.22

Thick cores gain fin area but lose airflow; at low rpm the net is close to zero. With fans off, natural convection is taken as 1 W/K per segment. The band is ±15 % on q: fin density, coolant flow and preheated case air. Pump speed matters little above roughly 1 l/min. Noise is the stock fan's curve plus 10 · log₁₀(fan count).

Air entering the radiator is case air, usually 5 to 10 K above room. Die temperatures sit above the coolant by the block and TIM delta, typically 25 to 45 K under load. Nothing here is measured; the same model runs in RadiatorTemp.