There’s no getting around the fact that today’s computer chips get incredibly hot. Despite all manner of efficiency improvements over the past few years, if you pack that many fast-switching transistors into such a small space, the end result is going to be a concentrated hotspot. Not only do the processor, graphics card and power supply all need active cooling, but your case will also have at least one fan it to shift airflow over the components and out the back.
The CPU has been a famous hotspot for a long time, and has been the target of increasingly larger and more efficient heatsinks, as well as water-cooling systems, in an attempt to cut noise. These improvements have been largely successfully too – the latest heatsinks and liquid-cooling products are far more effective and quieter than Intel’s reference coolers, or indeed any heatsinks from ten years ago too.
Meanwhile, graphics cards have seen some leaps forward in terms of both efficiency and cooler design, so much so that many Nvidia models can now run at modest loads with their fans switched off. Fanless power supplies are readily available too, and the latest silent models can dish out over 500W while still sporting 80Plus badges, which is enough power for most single-GPU systems.
Over the next few pages, we look at how to build a silent PC that’s also equipped for lengthy gaming sessions, maximising the effects of conduction and convection. However, we’ll also cover numerous ways to cut down the noise in your existing PC, taking sound readings to see which options offer the best bang per buck.
The right parts
Creating a silent PC is theoretically fairly easy – you just need to remove any parts that create noise, such as fans, pumps and hard disks. What isn’t so easy is then providing enough cooling for your hardware. We had to make two very small compromises with our PC build – there’s a fan on our graphics card and a single 120mm case fan. As Nvidia’s Pascal GPUs are so efficient, though, we decided to use a GTX 1060, which can actually turns off its fans for the majority of the time, allowing us to create a powerful gaming PC that only requires a little fan-assisted cooling in games.
We also include options for building totally a fanless system, but since gaming audio would likely drown out any noise from this graphics card anyway, we felt it was worth making these two small compromises in order to build a system capable of 2,560 x 1,440 gaming in the latest games, rather than mediocre performance even at 1,920 x 1,080.
Secondly, ditching all your fans can be dangerous in a high-end system, but you can have fans spinning slowly and creating airflow without being audible. More importantly, on a particularly hot day, a passive cooling system may not be sufficient to deal with the heat. In order to avoid stability issues under all conditions, it’s important to include one fan that can kick in if the machine gets too toasty – think of it as a fail-safe. Anyway, without further ado, let’s look at the hardware.
CPU and heatsink
Intel Core i7-6700K – $459
Nofan CR95C IcePipe – $200
With the thermal design power (TDP) of even top-end Intel Skylake CPUs dipping below 100W, there’s plenty of options for dealing with the heat produced by a stock-speed processor. To push our theory to the limit, we’ll be using a Core i7-6700K – the most powerful Intel CPU available with a TDP of less than 100W. Sadly, all the current Broadwell-E CPUs have TDPs of 140W, which is asking too much of any fanless CPU coolers short of using a massive external water-cooling radiator. That’s an option, of course, but in this feature we focus on keeping all the hardware inside the case and minimising costs.
There are plenty of examples of super-large heatsinks being able to passively cool CPUs, and they rely on the principle of convection.
You have a couple of options here, but the most popular one is Nofan’s CR-95C IcePipe. This huge heatsink uses 160 small heatpipes to create a massive surface area that’s effectively cooled by convection in your case. With a TDP limit of 95W, it should be able to cool an Intel Core i7-6700K, which has a TDP of 91W.
There are some downsides to the CR95C, though, which are mainly due to its size. You’ll be limited to using low-profile memory that’s shorter than 32mm tall, and you won’t be able to install or remove it with the heatsink installed. Some motherboards may have heatsinks that are too tall to sit under the CR-95C as well, but those on our Asus Maximus VIII Ranger are quite sizeable and there was still around 12mm of additional clearance available. We measured a maximum height limit of 36mm for motherboard paraphernalia – any taller and you’ll risk these parts fouling the heatsink.
The CR-95C also reaches a long way down the motherboard. As a result, on our Maximus VIII Ranger, the heatsink ended up obscuring the top 1x PCI-E slot, but it did at least leave the 16x PCI-E slot clear – just. Our graphics card doesn’t come equipped with a backplate, which is just as well as it may have ended up touching the CR-95C. Finally, using a fanless cooler such as the CR-95C means you’ll need to choose your case carefully. You’ll need at least 7mm of clearance between the edge of your motherboard and the top of your case, although thankfully, this revised version of the heatsink is smaller than the original version, which had compatibility issues with some cases.
Another consideration is ventilation – you want plenty of vents, especially in the roof, to enable convection to work its magic and allow the heat emitted by the cooler to escape – as hot air rises, it’s best for it to escape through the roof of the case, so a case with a minimum of two 120mm mesh vents in the roof directly above the heatsink will get you the best results.
MSI GTX 1060 Gaming X 6G – $395
We thought long and hard about our choice of graphics card. There are fanless cards available, but they usually use older, low-power GPUs, which will offer very limited performance. There are also large heatsinks for existing GPUs, but these can be tricky to install, plus they’re usually humongous and often require fans anyway. As we’ve already mentioned, using a large, fanless water-cooling radiator would work here, but you’d need at least a quad 120mm-fan model to passively cool a modern high-end GPU during lengthy gaming sessions.
There’s a much easier and cheaper solution to this problem, though, which is to take advantage of Nvidia’s highly efficient Pascal architecture.
Many Pascal cards use heatsinks that can cool these GPUs passively at low to medium loads, and only require their fans to spin up under heavy loads in games. We’ve opted for an MSI GTX 1060 Gaming X 6G, which can switch off its twin fans under low loads – almost any new GTX 1060 does this, so there’s plenty of choice.
We’ll also be looking at how to fine-tune the fan response in MSI’s Afterburner tuning utility, in order to extend the fanless operating time, so the fans only spin up at maximum load. This tweak means that the GPU won’t throttle its performance, which is a real possibility if you use a third-party cooler in a completely fanless configuration.
Of course, this minimal use of active cooling does mean our PC won’t be 100 per cent silent all the time, but it’s a worthy compromise for a huge increase in performance. Alternatively, there are completely fanless options too, such as Palit’s GTX 750 Ti KalmX. Sadly, we couldn’t find any more recent or more powerful fanless graphics cards, but this situation may change once Nvidia’s new GTX 1050 is established, so keep your eyes peeled. If you want to opt for another model of graphics card, just make sure it offers a passive cooling mode – some cards don’t support passive cooling by default, although you may be able to force fanless operation using a utility such as Afterburner.
Motherboard and memory
Asus Maximus VIII Ranger – $249
16GB 2666MHz GeIL Dragon RAM – $150
As we’ve already mentioned, the Maximus VIII Ranger is compatible with the Nofan CR-95C and the heatsink just about clears this motherboard’s primary 16x PCI-E slot too. Smaller motherboards may run into issues here, so we advise against opting for micro-ATX or mini-ITX motherboards.
Another advantage of the Ranger is its ROG EFI. Specifically, if you want to have a modicum of active cooling for hot days or lengthy gaming sessions, Asus’ EFIs are great for tuning your case fans – you can make them switch off below certain temperatures, which we’ll discuss later. In addition, the Ranger has good heatsinks, so it should be able to cope in a passively cooled case. You can, of course, use any compatible motherboard, but it may not be able to tune the fans so precisely.
You also need memory that won’t clash with the huge cooler. Despite its size, the Nofan CR-95C does have a reasonable height limit for memory modules, but the 32mm limit rules out the likes of Corsair’s Vengeance LED memory. We ditched memory heatsinks entirely with our choice, and opted for GeIL’s low-profile 2666MHz Dragon RAM.
512GB Samsung 850 Pro – $230
Once you’ve sorted out fan noise, the other key step on your quest for silence is ditching your hard disk and only using SSDs. Once you remove all the other noise sources, a hard disk can become the main sound producer in your case, and a highly annoying one too. There’s another reason not to use hard drives in a quiet PC too, which is heat.
Hard disks don’t dish out the same level of heat as a CPU, of course, but they do produce significantly more heat than a typical 2.5in SSD, so using solid state storage is a double-edged sword in a quiet PC. Assuming you don’t use a NAS, completely ditching hard drives will mean spending a lot more money if you need a decent amount of storage space, but the prices of even 1TB solid state drives are coming down now.
We used a 512GB Samsung 850 Pro in our system, but it’s also well worth considering the cheaper Evo model, which costs around $220 with a 1TB version costing under $450. The M.2 version of the 850 Evo is now slightly cheaper too, but unfortunately, despite the manual saying otherwise, the Maximus VIII Ranger doesn’t support SATA-based M.2 SSDs.
Jonsbo UMX4 – $199
Perhaps the most important decision you need to make when building a quiet PC is which case to use. We’ve mentioned that top roof vents are vital, and you ideally open mesh sections rather than angled panels, as the latter will only serve to hinder the convection movement of air in the case. Your case will also need at least 7mm of clearance above the top of the motherboard for the Nofan CR-95C heatsink, and ideally mesh sections in the base and front panel too. The more convection airflow you can achieve, the cooler your hardware, and if you choose a semi-passive graphics card (like ours), you’ll be able to keep its fans switched off for longer.
As well as convection, you also need to consider thermal conduction when buying a case. Lots of plastic should be avoided, and it’s worth investing in an aluminium case as opposed to steel. The former has a thermal conductivity rating nearly seven times higher than steel, and an entire PC case can end up acting like a radiator, adding to your PC’s ability to cool itself without fans.
We searched for such a case and managed to find one that should not only perform handsomely but also costs under $200. The Jonsbo UMX4 is an ATX case with an aluminium outer shell plus large vents in the base and roof thanks to a bottom-to-top cooling arrangement, which is ideal for convection. The UMX4 is also big enough to accommodate the Nofan heatsink, with the top vent sitting directly above it to allow the heat to escape.
Corsair RM550x 550W – $150
Many PSUs support semi-passive operation these days, from small SFX PSUs all the way up to 2KW monsters.
At low loads, these power supplies switch off their fans, just like semi-passive graphics card coolers. In general, modern PSUs made by decent brands are very quiet anyway, even under moderate loads, but unlike graphics cards, there’s plenty of fanless PSUs from which to choose. Some of them have limited connectors and often limit the number of PCI-E plugs, though, so check the specs before you splash out, especially if you’re using a discrete graphics card. Our GTX 1060 only requires a single 6-pin PCI-E connector, so there was plenty of choice.
In the end, we opted for a Corsair RM550x 550W PSU. This power supply offers a Zero RMP fan mode when under low and medium loads, and the fan is only kicked into action when it’s needed. It has two 6+2-pin PCI-E connectors, so it could potentially power a dual-GPU system too, as long as its power requirements didn’t exceed 550W and it doesn’t use two PCIe power ports. It’s a modular unit, too, so that helps keep our case nice and tidy.
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