be quiet! Silent Loop 280mm AIO CPU Cooler Review

Introduction

Manufacturer: be quiet!
Model: Silent Loop 280mm
Price: £129.99 MSRP (at time of review)

We have had a few products for be quiet! recently showcasing their work producing cases and power supplies which have highlighted their German passion for quality and precision engineering as well as their almost savant level of determination in making the quietest products available. Today we see yet another branch of the company with the same focus and goals when it comes to CPU cooling. The brand new Silent Loop series of coolers marks a new chapter for the company as it releases All-In-One liquid cooling solutions for the first time.

The Silent Loop series is available in 120mm, 240mm and 280mm radiator sizes and it’s the 280mm variant that I have the pleasure of working with today. Fitted with two Pure Wings 2 140mm PWM fans, reinforced flexible tubing and complete with a fill port to top up liquid after a prolonged period as well as three years warranty, be quiet! may have thought about everything to make this a success, but these external factors will pale into insignificance if the heat transfer plate and innovative new pump aren’t up to the task. The pump in question is their unique new ‘decoupled reverse-flow’ pump, designed to pull water through the cold plate instead of push it which reduces the speed the pump needs to run at thereby reducing noise and vibration compared to rival AIOs.

be quiet! have produced a video to introduce their new range which I have included below.

Before we sink our teeth into the cooler we should get through the formalities, and that means taking a gander at the rest of the features and specifications as well as a close-up look at what’s in store for us.

Features

• Innovative decoupled reverse-flow pump runs smoother, quieter and with less vibration than conventional pumps
• Full copper radiator for an impressive cooling performance
• Two Pure Wings 2 PWM fans provide quiet operation with high air pressure
• Customized fan speed thanks to PWM function
• Easy handling due to flexible bend-protection tubes and convenient mounting
• Full copper parts and a refill port extend the product’s lifespan
• Nickel-plated cold plate allows optimum use of heat-conducting metallic paste
• Compatible with Intel® and AMD™ sockets
• 3-year manufacturer’s warranty
• Product conception, design and quality control in Germany

Specifications

Closer Look

Starting with the box, and I apologise for the poor image quality, I had my camera on the incorrect setting.

The front of the box shows the pump unit and radiator with the fans attached. There are a few features of the products listed in various European languages underneath.

The back of the box has some more information about the company, the product features and highlights the benefits of both the Pure Wings 2 fan and the new Reverse Flow pump. This information is repeated in German.

The side of the box shows the product features printed in a European language (sorry, I don’t know which one) and the final side is again repeated in three more. This side also shows the technical specifications for the cooler and fans.

Altogether you receive the cooler, two Pure Wings 2 140mm fans, various fittings and a manual that lists all the relevant info and instructions in various European languages.

The powerhouse of this unit is of course the innovative reverse-flow pump which draws liquid through the cold plate instead of pushing it. this feature reduces the necessary speed of the pump which in turn reduces noise and vibration (which adds to noise). You can see what appear to be standard water cooling fittings which may allow for expansion of the loop or customisation. You can also see that the black flexible tubes are surrounded by a spring reinforcement to allow for tighter loops with less risk of kinking that causes flow restriction increasing the heat of the liquid as it spends more time next to the heat transfer plate.

The cold plate in question is all copper with a nickel plating overcoat to protect it from corrosion and tarnishing. In this image we can also see the fill port we previously mentioned as well as the end of the braided cable that provides power to the pump.

The other end of this closed loop is of course the radiator which is a full copper affair and again sees those universal fittings on the pipes. The Silent Loop series is available in 120mm, 240mm and 280mm radiators, and it is the 280mm that we have reviewed.

The loop would of course be incomplete without a set of fans to blow or suck air through the radiator. For this loop be quiet! recommend that you set up a blowing or push configuration. The included fans are 140mm Pure Wings 2, and all black fan with only the logo and printed information on the rear giving any break to that austere look.

Test Setup

CPU: Intel Core i7 4770k
Motherboard: MSI Z97I Gaming AC
Memory: 8GB (1x8GB) Team Group 2666MHz
Cooler: Thermalright Macho 120 SBM 
Thermal Paste: Noctua NT-H1
Storage: Sandisk Ultra II 240GB
PSU: XFX XTR 850

Installation

Installation and testing were carried out on a test bench rather than inside a conventional case. While this has the benefit of being easier to physically install as there is not as much stretching as well as easier access to motherboard jumpers and sockets, it has the disadvantage of not having any reduction in sound so what I hear may be more exaggerated than if it were in a case.

Thermal performance

Thermal performance is judged on four factors overall; the idle temperature at stock and overclocked speeds, as well as the loaded temperatures at stock and loaded speeds. During the testing, whether that be the idle or loaded testing, the system is either at idle or full load for a duration of five minutes before any readings is taken. The average temperature across all four cores is then noted down and used as the results. All room temperatures are recorded beforehand as well as during the test to ensure that the delta temperature is as accurate as possible.

Installation

Installation was a little fiddly as the backplate is only secured by sticky tape instead of being screwed in place prior to attaching the cooler. The pegs that the pump unit screw into are pretty small, only just poking past the motherboard, and are held in place by washers. Unfortunately, they are nor very tightly secured by those washers so more than once I had to catch a peg before it was lost for all time behind the back of my worktop.

Aside from that though, everything else about the installation was pretty smooth. The screws are held in place as they are bolted on to the pump/cold plate before being screwed down onto the backplate so at least I was able to hold the pegs securely from behind the motherboard while screwing in by hand from the front before finishing up with a screwdriver.

While be quiet! have designed the pump and loop circuit from the ground up, I have come across the installation procedure before as it is identical to that used by Fractal Designs in their for their  Kelvin S36, S24 and T12 liquid coolers which are currently sitting pretty in the Top 5 of the overclocking thermal chart. This leads me to believe they are manufactured by the same company which is great news judging by the FD’s performance and quality.

Speaking of performance, let’s take a look at the results of thermal testing…

Thermal Performance

Jumping straight into the top 10 at stock speeds while the CPU is idle is a great start for the Silent Loop.

With the CPU fully loaded the results are less thrilling, however without an overclock you can still be certain that you are not going to overheat the chip.

Jumping up a notch and pushing the CPU to 4500MHz we again see a strong showing when the CPU is idle and for light working conditions you should see that still being the case.

I expected to see the be quite! cooler struggle when we pushed the overclocked chip to full load but instead it shows a good result in the middle of the table. Maybe not the strong showing that was given by the visually similar Kelvins but with a focus on acoustics as well as thermals we can’t realistically expect them to come out top of the league.

Conclusion

Rounding up my time with the be quiet! Silent Loop 280mm and starting at the beginning… installation was not the easiest but it wasn’t too distressing. Aside from the pins popping out from the backplate, it was a simple process and easy for a novice to follow without struggling.

Thermals were good, not mindblowing, but adequate and enough to allow for a fairly reasonable overclock without frying anything. Part of the deal with this cooler is that it not only keeps the CPU cool (which is handy) but it does so with a very specific target of low noise. To this end we cannot expect to have the best cooling performance as there is a tradeoff and finding the right balance is key.

So how were the acoustics? Very good indeed. The low vibration, low noise design of the pump and cold plate works exceptionally well. With the fans turned off it was almost impossible to tell that the pump was running either by listening with my ear six inches away from it or by touching it. The only real way was through vibration on one of the tubes as water flowed between it and the radiator. Thermals are tested with the fans running at max speed and that invariably makes for a very noisy office irritating all around for the duration of the tests. This time the annoyance factor was noticeably less because instead of a deafening tornado it was more the sound of a strong wind from the testbench. Still loud enough to hear of course but if you take into account that this will invariably be placed into a closed case by the end user the sound levels will drop substantially even at max RPM.

Design wise, as I have mentioned before, things are visually very similar to the Fractal Designs Kelvin series, that’s followed through to the all copper manufacturing and the decision to use what appear to be standard water cooling fittings instead of the more traditional sealed, bonded tube connectors. This decision in addition to the inclusion of a fill port means that should you wish to expand the loop you have that option available to you. If you are going to add extra components to your loop then you will probably have to give up some of the quietness factor by adding extra fans and perhaps even an additional pump to keep things flowing, but even without adding to the loop those fittings open up interesting possibilities like colour matching the tubing to fit a theme or even going for rigid pipework.

Final thoughts on the be quiet! Silent Loop 280mm cooler are that it aims for a target user and hits that target full on. be quiet! seem to have had a chosen thermal performance mark in mind and then asked the question, ‘How quiet can we make it and still hit that mark?’. That thermal performance target is sufficient to allow for a decent overclock and still have a little headroom while the acoustic levels are such that you can stand next to the testbench and still hold a conversation while talking quietly. So, if you are in the market for something quiet and you overclock and you may become adventurous with your colour theme later on (or straight away) this is certainly something you should consider. Indeed, if those are your criteria then there really is nothing else on the market that fits the bill so nicely, short of going for a full custom setup.