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Be Quiet! Pure Power L8 700W Power Supply Review

Manufacturer: Be Quiet!

Efficiency, Differential Temperature and Noise

Efficiency

Efficiency is defined by the power output divided by the power input and is usually expressed as a percentage.  If a PSU were a 100% efficient (which none are) 700 watts of AC power going in would result in 700 watts of DC power coming out (with no waste heat to dissipate).  In the real world there are always inefficiencies and power is lost in the form of heat during the conversion process. Newer revisions to the ATX12V Power Supply Design Guide V 2.2 have continued to increase the efficiency recommendations for PC switching mode power supplies and now lists both required and recommended minimum efficiencies.

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We measured the AC power input to the Pure Power L8 700W PSU with an Extech power analyzer while the total DC load was found by adding all the individual +3.3V, +5V, +12V, -12V and +5VSB loads together. 

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The overall efficiency of the Pure Power L8 700W power supply is good and meets the criteria for 80Plus Bronze certification, even while operating on 115 VAC and at elevated temperatures. 

80 Plus Program

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Note 1: Power Factor ≥0.90 (50% to 100% Load)
Note 2: Tests conducted at room temperature (25°C)

Differential Temperature and Noise Levels

To simulate real world operation, some of the warm exhaust air from the PSU under test is recirculated back to the intake through a passive air duct, which allows the PSU air inlet temperature to increase with load, just like it would in a real PC. 

The differential temperature across the 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
Delta T = 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 ~27 dBA.  I was not able to take SPL readings at the higher loads due to the background noise generated by all the DC Load cooling fans cycling on and off.

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At low to mid power levels (10-50% load) the cooling fan was virtually silent. Even when delivering 350W (50% load) the cooling fan noise was barely detectable. I was not able to measure the SPL at the max load due to all the programmable DC load cooling fans cycling on and off, but subjectively the fan gets pretty loud at full load.
 

October 1, 2013 | 07:41 AM - Posted by Anonymous (not verified)

Is it MADE in Germany too ?
If it is...I want !

October 6, 2013 | 07:54 AM - Posted by Anonymous (not verified)

No.
they use rebranded or made-by units from FSP and seasonic.
Buy either seasonic or get the XFX pro black FM/Lepa G series.
Both are made by seasonic, but cheaper AND better than most beQuiets.

October 1, 2013 | 07:51 AM - Posted by Anonymous (not verified)

Only one place..in City Of Industry...carries them...and ALL models are out of stock !
What good is that ?

October 1, 2013 | 07:56 AM - Posted by Anonymous (not verified)

I meant local...COI not far for me...Newegg has 1000Watt Gold for $259.99 !
http://www.newegg.com/Product/Product.aspx?Item=N82E16817222005

October 1, 2013 | 09:21 AM - Posted by Anonymous (not verified)

Great review, great product, I know what my next power supply will be!

October 6, 2013 | 07:56 AM - Posted by Anonymous (not verified)

they use rebranded units from FSP and seasonic.

Buy either seasonic or the XFX pro black FM/Lepa G series.

Both are made by seasonic, but cheaper.
AND better than most beQuiets.

March 10, 2014 | 10:22 PM - Posted by Anonymous (not verified)

Read the article:

"Be Quiet! appears to be using the HEC Group as the OEM for the Pure Power L8 700W power supply (instead of Seasonic who is the OEM for the Dark Power Pro 10 we reviewed earlier this year"

Spouting opinions as fact - stupid dickhead

October 8, 2013 | 03:16 PM - Posted by Löwenchen (not verified)

Well bought it anyway it'll come in a few days. As long as it makes clean power and is silent it's fine by me so we shall see!

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