INTRODUCTION

   Last Friday a friend of mine called and asked if I could take a quick look at his 3 years old desktop computer since it wouldn't turn on and he had important work to do. Well we agreed for him to come by the lab/office next morning and when he did come it must have taken me less than 2 minutes to notice that his power supply unit was fried (smell gave it away really). To my surprise the moment I took off the side panel I saw something I hadn't seen for many years a cheap OEM PSU model (I seriously doubt it cost over USD30/30Euros) much like the ones I had in my systems up until roughly two decades ago (just before the first "serious" models made their appearance in the market). Unfortunately, it seems that there are some system builders around that still use such cheap OEM PSU's and people who are not into computers don't know what they are getting (fortunately just the PSU was fried). In any case the point I wanted to make is that PSU's are far more important today than 20+ years ago since today they power more advanced components so spending more for one is always a good idea. After reviewing the Pure Power 11 700W model by be quiet! last month some of you asked if we could also take a look at the CM (Cable Management) version and so today with us we have the Pure Power 11 700W CM.

   be quiet! is a premium brand of power supplies, PC cases and cooling solutions for desktop PCs. Consistently the leader in the German PC power supply market since 2007*, be quiet! is one of the most successful PSU brands in Europe. This enduring success is largely thanks to the typical German passion for quality and precision. All product conception, design and quality control is performed in Germany. German expertise is evident the moment an idea is born and throughout the entire design and production process. be quiet! never releases a product until it meets the highest expectations. All materials used – from the smallest screws to the metals in the cases – are tested to rigorous standards. That is why be quiet! power supplies, PC cases, CPU coolers and case fans are among the most silent, powerful and reliable on the market. Innovative engineering concepts coupled with an uncompromising choice of premium materials and world-class manufacturing quality make be quiet! second to none when it comes to noise reduction. With over ten years of experience, be quiet! are truly the quietness experts.

   The Pure Power 11 CM line of power supply units by be quiet! includes semi-modular models available in 400/500/600/700W outputs. In terms of features and specifications the Pure Power 11 700W CM (L11-CM-700W) model which we have here is very similar to the "regular" non-cm model we reviewed last month (aside of course its semi-modular design and flat modular cables) so both have a peak power output of 840W, are 80 Plus Gold certified (electrical efficiency up to 92%), have two 12V rails (56A total with a maximum supported power of up to 672W), support multiple graphics cards (four 6+2 pin PCIe connectors), have active PFC and DC to DC power conversion and come ready with a plethora of available electrical protections including OCP (over charge protection), OVP (over voltage protection), UVP (under voltage protection), SCP (short circuit protection), OPP (over power protection) and OTP (over temperature protection). Also, just like last time be quiet! covers the entire Pure Power 11 CM line with a 5 year limited warranty.

SPECIFICATIONS AND FEATURES

PACKAGING AND CONTENTS

Just like every other PSU by be quiet! the Pure Power 11 700W CM model arrived inside a black box that has a large product picture at the front right beneath the company and 80 Plus Gold certification logos and just above its main features.

The features list is also printed on both sides of the box in 5 different languages.

At the rear of the box we see the electrical specifications of the unit, its measurements and the available power connectors.

Be quiet! has placed the unit inside a bubble wrap protective.

Along with the Pure Power 11 700W CM, its modular power cables and its power cord you will also get 5 cable ties, 4 mounting screws and the user manual.

THE PURE POWER 11 700W CM EXTERIOR

Although the hardwired cables of the unit are round and sleeved the modular ones are flat.

As mentioned several times already the Pure Power 11 700W CM is a semi-modular power supply unit.

A 135mm intake fan is used to cool the internal components of the Pure Power 11 700W CM.

Be quiet! has placed their logo on one side of the housing and a sticker with the electrical specifications of the unit on the other.

All modular connectors are both different in size and tagged while the hardwired cables are sleeved all the way to the interior of the unit.

At the rear of the housing we find the usual honeycomb perforation, the on/off power switch and the power port.

THE PURE POWER 11 700W CM INTERIOR

The Silent Wings model used in the Pure Power 11 700W model is a rifle-bearing fan that can reach up to 2000RPM.

Interior design is clean and once again looks like this unit was manufactured by FSP.

Primary capacitor is manufactured by the Taiwanese TEAPO and is certified for use up to 85 degrees Celsius.

Secondary capacitors are also manufactured by TEAPO but are certified for use up to 105 degrees Celsius.

TEST BED

TESTING METHODOLOGY

     Using a dedicated measurement instrument such as a Chroma or a SunMoon to test power supply units is without doubt the most ideal and accurate way (not to mention the fastest) to do that currently. However it's certainly not the only way there is and so pretty much anyone can test a power supply unit just by using a computer. Certainly limitations do apply and so you can't really test a 1000W power supply if your system only uses 500W at peak loads and that's why many years ago i put aside certain hardware components for the purpose of building a dedicated PSU test rig. True it may not be as accurate as the above mentioned solutions but it comes really close and is in fact closer to real world usage. So as always we ran several games with maximum graphic options enabled at a resolution of 2560x1600 in order to stress every hardware component and increase the overall power demands of the system. The Passmark BurnIn Test was also used to overstress the components in an effort to provide the most accurate results possible. As a final test we also used the latest OCCT 4.4 software and its dedicated PSU testing suite since it can really bring a power supply to its knees after inside a few minutes.

     Rail stability was checked/measured with the CPUID Hardware monitor and a Metex multimeter which also recorded the system load in idle and in load. As always try to remember that the power consumption numbers listed in the graph are the highest (Peak) ones recorded during the entire duration of the tests and not the average ones. Noise levels coming from the fan were recorded using the high precision HD600 ExTech Sound dBA Meter from the rear of the unit and at a range of no more than 5-10cm. Readings under load are recorded the exact moment we manually switch the fans of all graphics cards from full speed to almost zero, that way the fan of the power supply does not have enough time to slow its RPM and so by doing this we get very accurate noise level readings. Needless to say in order to get 100% accurate readings you need to have a noise isolated room for that exact purpose, something which is quite impossible unless you are working inside a real lab (some people use very small noise insulated boxes but due to their size both heat and noise exceed normal levels and so the results can't really be considered to be 100% accurate). Also do take into account that since all noise measurements take place from just 5-10cm away the final noise levels to reach your ears will be considerably less.

TEST RESULTS

CONCLUSION

   After taking a look inside the Pure Power 11 700W CM (semi-modular) model it’s clear that it’s almost identical to the Pure Power 11 700W model (hardwired/fixed wires) we reviewed last month. Now as some of you may be aware hardwired power supply units usually outperform their semi-modular or fully modular counterparts when it comes to rail stability but it’s clear from our charts that this isn’t the case with the Pure Power 11 700W CM since it produced even “tighter”/better results. Audible levels are also a notch down from what we recorded from the Pure Power 11 700W (even though both units use the same fan) so that’s also a plus. (unfortunately our test rig with a single GTX295 card only used 88% of the units maximum power output so noise levels could increase even further but the same also applies for the hardwired/fixed wires version).

   At the moment of this review the Pure Power 11 700W CM model (L11-700W-CM) may still not available in the USA (MSRP however is set at USD94.99) but it’s available in the EU for a price of 99Euros (Amazon.co.uk) which we feel is quite balanced for what you’re getting. You can always opt to save a few bucks by getting the fixed wires version (roughly just USD15/13Euros less) but the cable management model performs slightly better and can save some space in the case if you don’t end up using all of its modular power cables. At the end of the day the Pure Power 11 700W CM may not be worlds apart compared to its fixed wires brother but it’s just better enough for us to give it our Golden Award.

PROS

- Build Quality
- Very Good Rail Stability
- 80 Plus Gold Certified
- Peak Output (840W)
- Electrical Protections (OCP/OVP/UVP/SCP/OPP/OTP)
- Semi Modular
- 5 Year Warranty

CONS

- Current Availability (USA)