Silent HTPC Hardware Guide

Nobody likes that buzzing computer noise.

This article will show which today’s hardware is appropriate for a completely silent HTPC and why.

PC Noise and Noisemakers

The main noisemakers inside a typical PC are its moving mechanical parts:

  • active cooling systems, and
  • electro-mechanical storage devices like HDD, ODD, FDD, etc.

Moving components produce sound because of friction in their bearings. Also, the airflow from fans can make noise when passing through ventilation holes or between cooler fins.

Of course, you can bring the overall noise level down considerably with proper greasing, lowering rotation speed, or rerouting the airflow. But strictly speaking, a PC with any mechanical parts can be considered low-noise only, but not noiseless or silent.

This article talks specifically about a dead-silent HTPC, with 0dB noise level, literally.

In order to get a dead-silent HTPC, you have to replace all active (moving) components in your build with passive (still) ones. Just change cooling fans to fanless heatsinks, HDDs to SSDs — and it’s done. However, no matter how simple this solution may look, in practice, it comes with a price in terms of costs and/or performance.

There’re several possible designs right below.

Dead-Silent HTPC Desktop

Choosing a silent desktop HTPC makes sense if you look for maximum flexibility and performance.

The downsides may be higher costs, larger overall size, and the need to pick right parts on your own.

CPU Cooling

The easiest way to have a passive CPU cooling system is to get a motherboard with a passively cooled onboard CPU: a motherboard with a pre-installed non-replaceable processor with a fanless heatsink on it.

Asrock J3455B-ITX
Asrock J3455B-ITX motherboard with heatsink

Such boards come in various small form-factors (sizes), including the most common mini-ITX and micro-ATX. Due to CPU’s integrated graphics card, CPU performance is quite enough for video playback and what else a simple HTPC needs. Besides, if the motherboard has a PCI-E x16 slot, it will allow adding a discrete GPU later, if necessary.

These motherboards CPU are very cost-effective. Sometimes you may pay for the whole set of CPU, heatsink, and the board itself less than you would for a “normal” socketed motherboard alone.

However, such motherboards are neither upgradeable nor repairable. If its CPU becomes too old or dies, it will be cheaper to buy the whole new board, than to fix the existing one. Also, their CPU are relatively weak and therefore are hardly suitable for real-time video transcoding or serious gaming.

Another option is to get an ordinary socketed motherboard, a CPU, and a fanless CPU heatsink separately (and to make sure that they correctly match each other). It will allow you to choose a motherboard and a processor which are best tailored to your specific needs.

Actually, you can make any heatsink fanless by simply taking its fan off, but the problem is whether the heatsink will then be able to cool your CPU and prevent it from overheating. Unfortunately, really good passive heatsinks are big and expensive.

Thermalright HR-22
Passive heatsink Thermalright HR-22

You might want to try a low-TDP CPU to keep heatsink’s size and price reasonable, but low TDP comes together with low performance, and eventually such a solution will be much like a motherboard with an onboard CPU described above.

It’s worth noting that contrary to what is written in marketing leaflets, CPU water cooling systems are not noiseless and often not even quiet. They have all kinds of noisemakers: fans, mechanical water pumps, and water flowing in pipes.

PSU Cooling

There’re two ways to get rid of fans in power supply unit.

The first one is to use a so-called Pico-PSU and an external fanless AC-DC power supply. It looks like a small circuit board with a set of connectors to plug into the mainboard, HDD, etc. It’s a DC-DC electricity converter: it takes DC (direct current) electricity from a power supply and converts it into what PC parts need. An AC-DC power supply unit takes AC (alternating current) from the wall outlet and converts it into DC. Notebook power bricks are a kind of such power supplies.

picoPSU
150W 12V pico-PSU from Mini-Box.com

The combination of a Pico-PSU unit and a fanless power brick makes a completely silent PSU, which is powerful enough to drive a simple HTPC, like one with onboard CPU. However, it’s total power output rarely exceeds 200W, that is not enough for a discrete GPU or a demanding CPU.

The second option is a “normal” PSU with passive cooling. It may be required when a Pico-PSU is not powerful enough for your setup. Passive PSUs are sparse, expensive, and quite big, but are able to output 500W and more.

GPU Cooling

Not every HTPC needs a discrete (stand-alone) GPU because the most of today’s CPU models already have an integrated video card inside. An IGP is just enough for video playback and even for light casual gaming.

However, if you’re interested in having a passive discrete card, it’s still possible to find some oldies like Nvidia’s GT series or a few experimental things like Palit KalmX. Yet they are not so powerful as their “active” counterparts, though.

Storage Devices

Noiseless storage devices are different kinds of SSDs, like traditional 2.5″ SATA drives or more recent M.2 modules. SSDs are completely silent, and their main problem may be their price. At the time small drives of 60 or 120Gb are quite inexpensive, but bigger ones (like 1Tb or more) still cost a few hundred dollars.

A 120Gb SSD is quite enough for an operating system and HTPC software if you don’t have a large media collection. Otherwise, you need to either spend money on big SSDs or to find alternative options (NAS, cloud storage, external HDD, etc.) to store your files.

Fanless Case

A silent PC case is simply a case with no cooling fans. Metal cases are better than plastic ones because metal dissipates heat more efficiently. Large cases with many vent holes are generally cooler since the airflow inside them is more active.

Bottom Line on Silent Desktop

So, a simple and cost-effective design for a silent desktop HTPC could be a motherboard with integrated CPU and fanless heatsink, a pico-PSU unit with a power brick, and an SATA or M.2 SSD.

A more advanced configuration with a gaming card and a full featured CPU will require a socketed motherboard with a GPU slot and a powerful passive PSU.

If a silent desktop HTPC is not an option, there’re two more alternatives below.

Single-Board Computer

Single-board computers like BeagleBone, Cubieboard, or today’s most popular Raspberry Pi are completely silent. They’re so low-power that don’t require any active cooling, and their own storage device is an electronic memory card (like SD card).

Raspberry Pi is quite inexpensive and works right out of the box. Due to hardware accelerated GPU it’s strong enough to play h.264 videos in Full-HD.

However, its software alternatives are pretty much limited to several Kodi clones and a number of Linux distros.

Fanless Nettop

A fanless nettop or small-form-factor PC is a low-power small-size “normal” PC.

The big brands prefer to use active cooling in many of their models (Intel NUC, Asrock Beebox), but less known companies make truly fanless nettops.

For storage most nettops use ordinary 2.5″ SATA SSDs, some newest models also have an M.2 slot too.

Compared to a single-board PC (e.g. Raspberry Pi), fanless nettops are not only completely silent but also more powerful. Plus they’re more functional because they can run both Windows and various Linux distros.

However, nettops are quite expensive and hardly upgradeable.

Conclusion

Building a silent HTPC became much easier today, than it was in previous decades. All the necessary parts are readily available from stores and all what’s needed is to choose a configuration best suitable for your particular needs.