Differential Temperature, Noise and Size/Weight

Differential Temperature and Noise Levels


To simulate real world operation the Ultra X3 power supply was mounted in a modified mid tower case (Lian Li PC60) for testing.  Some of the warm exhaust air from the PSU under test is recirculated back into the case, which allows the internal case air temperature to increase with load, just like it would in a real PC.  The internal case air temperature is allowed to increase up to 40ºC and then held constant from then on at 40ºC. 


The differential temperature across the Ultra X3 power supply was calculated by subtracting the internal case air temperature (T in) from the temperature of the warm exhaust air flowing out the back of the power supply (T out). 


Thermocouples were placed at the air inlet and exhaust outlet. The ambient room air temperature was 23ºC (74ºF) +/- 0.5ºC during testing.


T out = temperature of air exhausting from power supply

T in = temperature of air entering power supply

ΔT = T out – T in


Sound pressure level readings were taken 3′ away from the rear of the case in an otherwise quiet room.  The ambient noise level was 29 dBA. 


Ultra X3 1,000W EE Modular Power Supply Review - Cases and Cooling 41


The Ultra X3 1,000W power supply was very quiet while operating at low to medium loads.  The fan speed increased to the point where it was noticeable at loads over 600W as temperatures also climbed, but never became objectionably loud.  The exhaust temperatures got quite warm at higher loads, but the X3 appears to be designed to handle these elevated temperatures thanks to the server class platform the X3 1kW is built upon.


Note: I am not able to take SPL readings at the higher loads due to all the programmable DC load cooling fans running.


Physical Size and Weight


The Ultra X3 EE 1,000W power supply measures: 150 x 86 x 200mm (5.9′ x 3.4′ x 7.9′ W x H x D).  Note the X3 1kW enclosure is a full 200mm deep (a standard ATX PSU is 140mm long) so make sure it will fit in your case before purchasing one.


And last but not least, a basic measures of any ATX power supply is the unit’s overall physical weight.  This may seem rather simplistic but it generally holds that more industrial grade components and larger heatsinks equal a better PSU.  The following graph illustrates how the Ultra X3 1,000W PSU compares to some other popular power supplies on the market.


Ultra X3 1,000W EE Modular Power Supply Review - Cases and Cooling 42

(click to enlarge)


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