Corsair H100i RGB vs DeepCool LS520computed

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

Corsair H100i RGBDeepCool LS520
Radiator240 mm240 mm
Core thickness27 mm27 mm
Stock fans2 × QX1202 × FC120
Fan rpm, datasheet480 – 2400500 – 1800
Pumpnot published3100 rpm max
Tubing400 mm410 mm
Dissipation at max rpm17.1 W/K16.9 W/K
Coolant, 250 W, 30 °C intake44.6 °C44.8 °C
Noise at max rpm, all fans–31.0 dB(A)

Coolant above intake at 250 W

0 10 20 30 40 0 20 40 60 80 100 % of max fan rpm LS520 H100i RGB 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 intakeH100i RGB rpmdB(A)LS520 rpmdB(A)Quieter
10.0not reachable–not reachable–
12.5not reachable–not reachable–
15.02300–175830.5
17.51779–136025.0
20.01424–108920.4
25.0982–751<15

The H100i RGB dissipates 17.1 W/K against 16.9 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.