be quiet! Pure Power 11 600W PSU Review

The Pure Power 11 Series sits squarely in the middle of the be quiet! power supply lineup. These units are semi-modular and are available in six different models ranging from 300W up to 700W. be quiet! designed the Pure Power 11 Series to offer the best combination of features at a popular price for mainstream enthusiasts. We will be taking a detailed look at the be quiet! Pure Power 11 600W power supply in this review.

Features & Specifications

And as you might expect, be quiet! remains focused on delivering virtually silent power supplies. be quiet! designed the Pure Power 11 Series to provide reliable operation with minimal noise for systems that demand quiet operation. To accomplish this be quiet! uses a 120mm fan that features ribbed fan blades and a wire-frame fan guard to help maximize airflow and reduce noise.

Four of the Pure Power 11 Series power supplies are certified to be compliant with the 80 Plus Gold criteria for high efficiency (700W, 600W, 500W and 400W) while two are rated 80 Plus Bronze (350W and 300W). In addition to the Pure Power 11 Series, be quiet! offers a full range of power supplies in ATX, SFX, and TFX form factors.

be quiet! Pure Power 11 600W PSU Key Features:

• 600W continuous DC output (ATX12V v2.4, EPS 2.92 compliant)
• Very quiet 120mm be quiet! cooling fan
• 80 PLUS Gold certified efficiency (up to 92%)
• User-friendly cable management reduces clutter and improves airflow
• Modern topology: Synchronous Rectification and DC-to-DC conversion
• Advanced GPU support with four 6+2 pin PCI-E connectors
• Meets the latest Intel C6/C7, ErP and Energy Star guidelines
• Active Power Factor correction (0.99) with Universal AC input
• Safety Protections :OCP, OVP, UVP, SCP, OPP, and OTP
• 5-Year warranty
• Product conception, design and quality control in Germany
• $84.90 USD (newegg.com, April 2019)

Specifications

The be quiet! Pure Power 11 600W power supply is rated for a combined, continuous output power of up to 600 watts at 40°C operating temperature (650W peak). The PSU incorporates two independent +12V rails, which can deliver up to 48A (576W) on the combined +12V outputs. The PSU includes universal AC line input (automatically adjusts the AC line voltage) and active PFC, which makes the unit more environmentally friendly to the local power grid. 

Pure Power 11 600W PSU Specifications (from the be quiet! website):

Packaging & Parts

The Pure Power 11 600W power supply was delivered to us from Newegg. The power supply arrived securely packed inside a standard retail box highlighting the unit’s main features and specifications.

The power supply is wrapped in plastic and protected by a cardboard insert. In addition to the power supply, the box contains a power cord, two bundles of modular cables, mounting screws, wire ties, and a multi-language User Manual.

Modular PCI-E (2) and Peripheral drive (3) cables

Image courtesy of be quiet!

A Detailed Look

The be quiet! Pure Power 11 600W power supply enclosure is painted matte black and measures 150mm (5.9”) long. The back panel includes an On-Off switch, AC receptacle and honey-comb grill area for exhaust airflow. The large intake fan grill is made up of multiple parallel wires for minimal restriction and good airflow.

The power supply uses a 120mm fan for cooling (BQ QF1-12025-MS). While the fan bears the be quiet! label it does not appear to match any of their mainstream fan products, like a Silent Wings 3, etc. However, it does incorporate sculpted blades that are designed to reduce air turbulence and noise. The fan is rated for 0.3A and 1800 rpm at 12 VDC.

The front panel includes five connectors for the modular cables, all nicely keyed and labeled. The Pure Power 11 600W power supply comes with a good assortment of two fixed (24-pin ATX and 4+4 pin 12VATX/EPS) and five modular cables. The fixed cables are covered with black plastic mesh sleeving while all the modular cables are the black flat ribbon-style.

Here are a few pictures showing the layout and components inside the be quiet! Pure Power 11 600W power supply.  The layout and build quality both appear good with plenty of spacing between components for good air flow. Be quiet! is using a modern topology that features Synchronous Rectification (SR) power conversion along with DC-to-DC voltage regulators located on a daughter card to provide good voltage regulation and high efficiency.

Most of the capacitors are non-Japanese made. For example the main bulk electrolytic capacitor is made by Teapo and rated for 330 uF, 420V, 85°C. Not our first choice but also not unusual to see in a mainstream, budget minded power supply.

DC Load Regulation & AC Ripple

PSU Testing Methodology

Establishing an accurate load is critical to testing and evaluating a PC power supply.  PCPerspective’s power supply test bench can place a precise DC load on the PSU under test.  Each power supply is tested under controlled, demanding conditions up to its maximum rated load (at 40ºC). Our current suite of tests includes:

• DC Load Regulation
• AC Ripple and Noise
• Efficiency
• Differential Temperature
• Noise

The be quiet! Pure Power 11 600W power supply was evaluated on both features and performance.  A full range of equipment was used to test the power supply under controlled load conditions. 

• (2) CSI3710A Programmable DC load (+3.3V and +5V outputs)
• (4) CSI3711A Programmable DC load (+12V)
• (3) 218W Precision resistor load bank (+12V)
• Switchable precision resistor load bank (-12V and +5VSB)
• Agilent 34401A digital multimeter (Accuracy ±0.0035% vDC)
• Extech 380803 Power Analyzer (Accuracy ±0.5% of full scale)
• DS1M12 “StingRay” digital oscilloscope (20M S/s with 12 Bit ADC)
• Powerstat Variable Autotransformer, 1.4 KVA, 0-140 VAC
• Extech Model 407738 digital sound level meter (Accuracy ±1.5 dB)

The following cables/connectors were used to connect the Pure Power 11 600W power supply to the PCPerspective power supply test equipment.

• (1) 20+4 pin ATX
• (1) 8-pin EPS/ATX12V
• (4) 6-pin PCI-E
• (6) SATA
• (3) Molex

DC Output Load Regulation

To simulate demanding and maximum loading conditions, the be quiet! Pure Power 11 600W power supply was connected to the load testers and supplied with a constant 120 VAC.  In this test we are interested in seeing how well a PSU can maintain the various output voltages while operating under different loads.

The ATX12V V2.2 tolerance for voltages states how much each output (rail) is allowed to fluctuate and has tighter tolerances now for the +12V outputs.  I have also included a second table of expanded tolerances (±1% to ±6%) for reference.

The following tables list the DC voltage results for the PSU while operating on 120 VAC, 60 Hz.

The Pure Power 11 600W power supply produced good voltage regulation on all of the DC outputs all the way up to 600 watts total load. All of the primary rails stayed within ±2%.

AC Ripple & Noise on the DC Outputs

The amount of AC ripple and noise present on the DC outputs was checked using a digital oscilloscope.  This AC component may be present in the KHz range where most switching power supplies operate or it may be more prevalent at the 60 Hz line frequency.  We adjust the O-scope time base to look for AC ripple at both low and high frequencies.  The ATX12V V2.2 specification for DC output noise/ripple is defined in the ATX12V Power Supply Design Guide.

Ideally we would like to see no AC ripple (repetitive) or noise (random) on the DC outputs – the cleaner the better!  But in reality there will always be some present.  I measured the amplitude of the AC signal (in millivolts, peak-to-peak) to see how well the power supply complied with the ATX standard.  The following table lists the ripple/noise results during all of the load tests for the main output voltages of interest.

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) 600 watts of AC power going in would result in 600 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.

We measured the AC power input to the Pure Power 11 600W 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.

The overall efficiency of the Pure Power 11 600W power supply is very good and easily meets the criteria for 80 Plus Gold certification, even while operating on 120 VAC and at slightly elevated temperatures.

80 Plus Program

Tests conducted at room temperature (25°C)

Differential Temperature & Noise Levels

To simulate a demanding environment, 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.

The Pure Power 11 600W power supply started out very quiet – virtually silent and stayed that way through mid-power. As the power supply approaches full output the fan ramps up quickly and at the 600W mark the fan noise was becoming noticeable.

Chart courtesy of be quiet!

Final Thoughts & Conclusions

The Pure Power 11 Series is designed to provide a good balance between performance and affordability.  Be quiet! appears to be targeting mainstream enthusiasts who want solid performance without paying for premium features.  The 600W model we tested delivered good electrical performance across the board and stayed very quiet well through mid-load.

The Pure Power 11 600W PSU delivered very good voltage regulation (±2%) with relatively low AC ripple and noise on the DC outputs.  Efficiency was also very good and easily met the requirements for 80 Plus Gold certification, which along with be quiet!’s 120mm fan resulted in virtually silent operation at low to mid power levels. The Pure Power 11 power supplies come with a good bundle of semi-modular cables, all of which are sleeved or flat ribbon-style for easy installation.

Some of the component choices reflect the price conscious, consumer oriented position of the Pure Power Series (85°C capacitors and non-Silent Wings fan for example) but we did not note any serious compromises. Of course we would prefer to see a higher operating temp and longer warranty but these are also in line with the Pure Power’s pricing structure.

The Pure Power 11 600W power supply is currently available and selling for $84.90 USD (newegg.com, April 2019), which puts it in line with some of the competitions 600W Gold power supply units (EVGA, Seasonic, etc.).

Note: The Pure Power 11 300W and 350W models are 80 Plus Bronze certified, not Gold.

Strengths:

• Quiet operation, virtually silent at low to mid-power levels
• 80 PLUS Gold certified (90~92% efficiency at 20-100% load)
• Very good voltage regulation (±2%) with low AC ripple and noise
• Fully modular, sleeved cable set
• Active Power Factor correction (0.99) with Universal AC input
• Safety Protections : OCP, OVP, UVP, SCP, OPP, and OTP
• 5-Year warranty

Weaknesses:

• Nothing major noted