Differential Temperature, Noise and Weight

Differential Temperature and Noise Levels


To simulate real world operation the OCZ ProXStream 1kW 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 a maximum of 40ºC and then held constant. 


The differential temperature across the ProXStream 1kW 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 ~30 dBA. 


OCZ ProXStream 1,000W Power Supply Review - Cases and Cooling 32


As I mentioned earlier, the OCZ ProXStream 1kW PSU was designed for performance, not quiet operation.   The single high-speed cooling fan does a good job of keeping the densely packed components within safe operating temperatures at the expense of noise.  Even under minimal loads, the ProXStream is relatively noisy and as the load goes up, it just gets worse.  Keep in mind this power supply is targeted towards die-hard gamers and high-end system builders, who most likely put performance far ahead of quiet operation.


Note: Unfortunately, I am not able to measure the SPL when the power supply is running at the higher loads because all the cooling fans on the programmable DC loads are also running at this point. 


Physical Size and Weight


The OCZ ProXStream 1kW power supply measures: 150 x 86 x 140mm (5.9′ x 3.4′ x 5.5′ W x H x D).  This is a very compact package considering the rated output capacity and is one of the ProXStream 1kW’s main features.


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 OCZ ProXStream PSU compares to some other popular power supplies on the market.


OCZ ProXStream 1,000W Power Supply Review - Cases and Cooling 33

(click to enlarge)


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