Difference between revisions of "Cooling Quietly"

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{{outdated2|most of the information in this page is for hardware 5+ years old}}
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This page will detail methods for keeping a Mythbox running quietly and cool.
 
 
Well, you don't want to drown out your nice sound do you?
 
 
 
There are several different approaches to keeping your system quiet and cool, so we'll look at them all in depth.
 
 
 
==Isolate noisy machine(s)==
 
One of the easiest ways to keep your Myth system quiet is to (basically) throw it in the cupboard — don't worry, this isn't as drastic as it sounds. As your probably know, MythTV (like most bits and bobs of Linux) is highly network aware, and will allow you to run a separate [[Mythbackend|backend]] and [[Mythfrontend|frontend]]. All of the noisy hot stuff, such as TV cards, hard drives, and Terahertz Athlons can be thrown into the backend and kept under the stairs; you can install a low-powered small machine under the TV. All of the control can be done from the frontend, which will just request TV streams from the backend over the network. The downside of this of course is that you need to be able to afford two separate machines, although it will make expandability much easier further down the road.
 
 
 
Viewing high-definition recordings requires much more processing power; decoding a 1920x1080 MPEG2 is much more intensive than viewing a 400x480 SD video of any format.  It is thus more difficult to quiet a high-def frontend when you likely need a CPU over 2 GHz and/or a hardware video accelerator ([[IDCT]] via [[XvMC]]).
 
 
 
There is however an alternative for the cupboard approach. Several CAT5 KVM extenders exist on the market. Such a device extends your VGA, mouse, and keyboard cables using CAT5 network cable. You can extend up to 30 meters. One setup in use includes two Aten CE220 KVM extenders to extend my Dual Head development box from the hallway closet into the living room. This setup now has only two LCD screens, a mouse, and a keyboard sitting in the living room generating zero noise. It also includes an SPDIF cable running from the living room amplifier and a cinch TV-out cable to the TV-set.
 
  
 
==Software solutions==
 
==Software solutions==
[http://linrunner.de/en/tlp/tlp.html TLP] can be used to set automatic power saving modes on modern Intel and AMD processors and is typically in the distro repositories.
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Modern hardware have power saving states that can be enabled through [http://linrunner.de/en/tlp/tlp.html TLP] that sets power saving modes on boot for modern Intel and AMD processors.  TLP is typically available in your distribution repositories.
  
 
==System components==
 
==System components==
Even if you can't avoid having your quad 30GHz Xeon Myth array sitting under the TV, there are still many ways you can reduce the amount of noise today's computers like to kick out. There are many specialist computing companies out there specializing in quiet hardware for use in [[HTPC]] environments, and I'll list a few of the products you might want to splash out on:
 
  
===Quieting fans===
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===Quiet fans===
  
 
PWM fans are the best option for cooling as the motherboard can control the speed based on the case temperature.  These have 4-pin connectors that will appear similar to the header for the CPU fan and may come with rubber mounting dampers which are highly recommended.  Ensure the motherboard supports a 4 pin chassis fan before purchasing.  The BIOS usually has options to select 'silent' operation where the chassis fan(s) may not spin up until needed.
 
PWM fans are the best option for cooling as the motherboard can control the speed based on the case temperature.  These have 4-pin connectors that will appear similar to the header for the CPU fan and may come with rubber mounting dampers which are highly recommended.  Ensure the motherboard supports a 4 pin chassis fan before purchasing.  The BIOS usually has options to select 'silent' operation where the chassis fan(s) may not spin up until needed.
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CPU coolers in modern processors (c2014) are typically quiet and no special attention is required.
 
CPU coolers in modern processors (c2014) are typically quiet and no special attention is required.
  
Quiet and/or adaptive power supplies units (PSU) can also help reduce noise by a considerable degree. There are some premium PSUs that just use a heatsink for cooling, and thus run totally silent. However, they don't do much for the cooling of your case! A better solution are high efficiency PSUs (80 Plus Gold) or a [http://www.silentpcreview.com/article601-page1.html pico-PSU] and choose a PSU with a rating closest to your computer usage.  It is highly recommended that a power meter is used to ensure that you will not exceed the supply rating of the PSU.
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Quiet and/or adaptive power supplies units (PSU) can also help reduce noise by a considerable degree. There are some premium PSUs that just use a heatsink for cooling, and thus run totally silent. However, they don't do much for the cooling of your case! A better solution are high efficiency PSUs (80 Plus Gold) or a [http://www.silentpcreview.com/article601-page1.html pico-PSU] and choose a PSU with a rating closest to your computer usage.  It is highly recommended that a power meter is used to check that you will not exceed the supply rating of the PSU.
  
 
===CPU choice===
 
===CPU choice===
'''Use a cooler processor!''' Several years back, CPUs kicked out a helluva lot of heat and caused systems to become uncomfortably hot. More recently, AMD and Intel have realized the error of their ways and modern processors are faster than ever, but without generating enough heat to melt your case. Assuming you're using a hardware capture device (either a DVB card or one of the TV cards supported by ivtv) and a reasonably good graphics card.  One of the good things about Myth is that 90% of the common functions don't require a powerful CPU at all, so you can often pick and choose the CPU that runs at the lowest power and heat output.
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One of the good things about Myth is that 90% of the common functions don't require a powerful CPU at all, so you can often pick and choose the CPU that runs at the lowest power and heat output.
 
 
See the section on frontend hardware to choose an appropriate CPU to meet your requirements.
 
  
===Low power computing===
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====Intel Processors====
Low power computing is running your processor at less than its full clock speed and voltage to produce less heat and use less energy. The heat produced by a particular processor increases linearly with increases in clock speed and quadratically with an increase in voltage (the change in heat production is the square of the change in voltage.) There are two ways to reduce your processor's voltage and clock speed. You can either have it done automatically if your processor supports such a function and you can do it manually.
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Modern Haswell era Intel processors are handled by the kernel p-state driver and have multiple sleep states (C1 to C10) enabling low power and low heat CPUs. This is typically handled automatically but the BIOS settings should be checked to ensure the BIOS is able to put the processor into these C-states. Use <code>powertop</code> to check if these low power states are being reached.
  
'''Automatic CPU frequency and voltage scaling'''<br>
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If maximum power usage is a problem, the highest frequency of the processor can be capped in the BIOS resulting in a drop in maximum power draw.  The processor will otherwise reduce frequency and voltage automatically. Otherwise, ''T'' versions of the Intel range are low power variants but may exhibit the same power draw at idle.
Notebook processors have had the capability to reduce their clock speed and voltage while idle to prolong battery life for about 10 years. Recently this capability has been added to desktop processors as well. AMD calls their frequency and voltage scaling "Cool 'n Quiet" and Intel calls their "Enhanced Intel SpeedStep." Cool 'n Quiet allows the processor to drop to about 1200 MHz for the Phenoms and and 800 or 1000 MHz on the other processors. Intel Pentium 4 or Pentium D processors with EIST idle at 2.80 GHz while the Core 2/Pentium Dual Core/Celeron 4xx or E12xx processors idle at 1.5x their effective frontside bus speed, which usually yields idle speeds of 1.2, 1.6, or 2.0 GHz. Processors that support frequency and voltage scaling:<br><br>
 
''AMD Processors''<br>
 
All Athlon 64 models<br>
 
All Athlon 64 X2 models<br>
 
Sempron 3000+ and faster on Socket 754<br>
 
All Semprons 3200+ and faster on socket AM2<br>
 
All Athlon LE processors<br>
 
All Athlon X2 processors<br>
 
All Phenom processors<br>
 
Socket 940 revision E (90 nm) Opterons<br>
 
All Socket 939, AM2, AM2+, and F Opterons<br>
 
  
''Intel Processors''
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====AMD Processors====
Pentium 4 6xx series except the P4 620 and a few early B1 stepping 6x1 series processors<br>
 
All Pentium Ds except the 820 and 915/920<br>
 
All Pentium Dual Cores<br>
 
All Core 2 Duos, Core 2 Quads, and Xeon 3000 series<br>
 
Celeron E12xx series<br>
 
  
Activating the automatic frequency and voltage scaling is accomplished by loading the appropriate cpufreq drivers for your chip and setting the cpufreq governor to "ondemand." This should be automatically done for you in most Linux distributions made in the last few years.
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'' If you have an AMD please add information in here. ''
  
'''Manual CPU frequency and voltage scaling'''<br>
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===Optical drives===
Those of you who know about overclocking may well want to experiment with '''underclocking''' and '''undervolting'''. This involves manually adjusting the CPU voltages and frequencies to a level below the stock voltages and frequencies. That can be accomplished by going into the BIOS and setting these values if your motherboard allows it. Some motherboards do not allow any frequency or voltage modification while others will only allow for you to overvolt the processor (such as abit boards.) You can also reduce the processor's operating voltages adjusting the EIST/Cool 'n Quiet voltage values using a tool like cpupower or Linux-PHC. Note that these tools are generally only useful for adjusting the voltages for the above-idle speeds, particularly on AMD processors as the voltage for the idle speed is typically not adjustable.
 
  
'''Buying a specially-designed energy-efficient CPU'''<br>
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A contributor to noise and vibration are optical drives running at 16x or 52x. To watch DVDs and play CDs you shouldn't need a drive faster than 1x DVD or 1xCD respectively. The DVD and CD specifications are written such that a DVD should playback video or video perfectly well at the drive's lowest available speed. Hence a drive with the lowest speed should be chosen as MythTV needs fast disc access is when ripping a CD or DVD.  You may also want to experiment with [http://freshmeat.net/projects/hdparm/ hdparm], [http://packages.debian.org/stable/utils/setcd setcd] or [http://noto.de/speed/speedcontrol.c speedcontrol]; All claim to be able to reduce the maximum speed of optical drives.
Intel and AMD both have lines of CPUs specifically designed to run at a lower thermal dissipation than standard CPUs. Intel's energy-efficient processors are unfortunately limited to servers and laptops but AMD sells lines of energy-efficient desktop processors. The original 90 nm Athlon 64 X2 EE line has a 35- or 65-watt TDP versus an 89 W TDP for the standard chips and the newer 65 nm line Athlon BE line has a 45-watt TDP versus a 65-watt TDP for the standard chips. Currently-shipping AMD energy-efficient processors have an "e" suffix, such as the Athlon X2 4050e/4450e/4850e and the Phenom X4 9100e and 9300e. Energy-efficient Opterons have the "HE" suffix.
 
  
'''Running a laptop CPU in a desktop motherboard'''<br>
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As of this edit there are no optical drives on the market that are specifically advertised as being quiet or having quietness as a feature. Some drives have "quiet" firmware/utilities available which will limit the speed to a more reasonable and less deafening level. Since almost all drives require that their firmware be upgraded using Windows or DOS you may run into difficulty attempting this method with a Linux based computer running MythTV. You do have the option of putting a drive into a Windows based computer, applying the firmware alteration, and then putting it back in your Linux based computer (a variation on this theme is to always have a [http://www.freedos.org/ FreeDOS] bootable partition).
Those of you who are even ''more'' adventurous might want to try running an efficient, low-power laptop CPU in a desktop motherboard in a "Mobile-on-Desktop" aka "MoD" setup. The best candidates for this setup are mobile CPUs that have the same socket as common desktop CPUs as motherboards are inexpensive and easy to find. Socket A Athlon XP-Ms and socket 754 Turion 64s are very popular to use in this manner. Socket 478 Mobile Pentium 4s and the lower-TDP Mobile Pentium 4-Ms can also be used, but there are occasionally issues with BIOS and SpeedStep support. There are a few motherboards with laptop-specific sockets like Socket 479, Socket M, Socket P, and Socket S1. They tend to be very expensive and hard to find.
 
  
===Vibration===
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==Chassis==
Vibration from wobbly components can often cause irritating buzzing noises. Regularly give your fans a clean by blasting them with compressed air (be careful as you can overspeed smaller fans), and if vibration seems to be a problem you can dampen your fans by placing rubber or silicone washers between the fan and the mounting. Other moving components (such as hard drives and optical drives) should be secured mechanically well. You could consider mounting your drives in a dampening cage or using anti-vibration grommets. Antec uses the latter to great effect. I'm personally a big fan of the [[Cooler Master]] 620's spring-clip mechanism of mounting optical drives; these are screwed in on one side, and are forced into a good fit by a spring clip on the other side.
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'''Keeping all those cables tidy''' can do wonders for airflow within your case, and do away with the need for more fans. You can tie bundles of power cables together using zip ties, braiding or spiral wrap.
  
Related to vibration are '''stupidly fast optical drives''' running at 16x or 52x or something similarly daft. To watch DVDs and play CDs, you shouldn't need a drive faster than 1x DVD or 1xCD respectively. The DVD and CD specifications are written such that a DVD should playback video or video perfectly well at the drive's lowest available speed, YMMV.
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It is possible to '''soundproof your case''' with acoustic material. This is essentially sticky-backed foam that does a lot to absorb noise from inside the case, although you'll need a case with enough free space inside to accommodate its thickness. I've never tried this myself, but a lot of people swear by it. Lian Li and Zalman make some very pretty (and pretty expensive) cases fitted with this sort of anti-noise technology as standard, so those of you who want a big, quiet case might want to consider splashing out on those.
  
As of this edit there are no optical drives on the market that are specifically advertised as being quiet or having quietness as a feature. Some drives have "quiet" firmware/utilities available which will limit the speed to a more reasonable and less deafening level. Since almost all drives require that their firmware be upgraded using Windows or DOS you may run into difficulty attempting this method with a Linux based computer running MythTV. You do have the option of putting a drive into a Windows based computer, applying the firmware alteration, and then putting it back in your Linux based computer (a variation on this theme is to always have a [http://www.freedos.org/ FreeDOS] bootable partition). If you have the choice between an 8x DVD drive and a 16x DVD drive, choose the slower (8x) one. The only place MythTV needs fast disc access is when ripping a CD or DVD. You may also want to experiment with [http://freshmeat.net/projects/hdparm/ hdparm], [http://packages.debian.org/stable/utils/setcd setcd] or [http://noto.de/speed/speedcontrol.c speedcontrol]; All claim to be able to reduce the maximum speed of optical drives. setcd may require a patch to work with newer drives, see debian bug [http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=367008 367008]. [http://www.silentpcreview.com/ SPCR] has a forum [http://www.silentpcreview.com/forums/viewtopic.php?t=33745 thread] on the subject. But there appears to be no definitive study of the comparative quietness of DVD/CD drives.
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Furthermore you can ''uncouple the case mechanically'' from whatever is underneath it, or whatever it's underneath.  Conducted noise which is then transferred by another device is a major component of the noise which a PC can put out &mdash; which explains the rubber mounts you can get for hard drives.  They're good for noise, but bad for thermal conduction.  (You ''do'' have a fan blowing directly on your hard drives, right?)
 
 
==Chassis quieting==
 
'''Keeping all those cables tidy''' can do wonders for airflow within your case, and do away with the need for more stupidly fast fans. You can tie bundles of power cables together using zip ties, braiding or spiral wrap (my personal favourite, since it's easy to apply and remove).  Don't forget [http://thetechzone.com/?m=show&id=126 The Art of Cable Folding] for those with tight wallets.
 
 
 
Last but not least, you can also attempt to '''soundproof your case''' with acoustic material. This is essentially sticky-backed foam that does a lot to absorb noise from inside the case, although you'll need a case with enough free space inside to accommodate its thickness. I've never tried this myself, but a lot of people swear by it. Lian Li and Zalman make some very pretty (and pretty expensive) cases fitted with this sort of anti-noise technology as standard, so those of you who want a big, quiet case might want to consider splashing out on those.
 
 
 
And, even more finally (:-), you can ''uncouple the case mechanically'' from whatever is underneath it, or whatever it's underneath.  Conducted noise which is then radiated by something ''else'' is a major component of the noise which a PC can put out &mdash; which explains the rubber mounts you can get for hard drives.  They're good for noise, but bad for thermal conduction.  (You ''do'' have a fan blowing directly on your hard drives, right?)
 
 
Standing the chassis on a piece of carpet, or even better, underlay will cut down on transmitted noise through the floorboards, plasterboard etc.
 
Standing the chassis on a piece of carpet, or even better, underlay will cut down on transmitted noise through the floorboards, plasterboard etc.
  
That'll about do it for now, hope you enjoyed the update ;)
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For more information on keeping your HTPC (and PCs in general) quiet the website [http://www.silentpcreview.com Silent PC Review] has some excellent guides, reviews and forums to provide you with all the details you need.  Their [http://silentpcreview.com/section5.html recommended hardware section] contains lots of hard numbers.
 
 
For lots of information on keeping your HTPC (and PCs in general) quiet the website [http://www.silentpcreview.com Silent PC Review] has some excellent guides, reviews and forums to provide you with all the details you need.  Their [http://silentpcreview.com/section5.html recommended hardware section] contains lots of hard numbers.
 
  
 
==Useful Links==
 
==Useful Links==

Latest revision as of 10:34, 11 December 2014

This page will detail methods for keeping a Mythbox running quietly and cool.

Software solutions

Modern hardware have power saving states that can be enabled through TLP that sets power saving modes on boot for modern Intel and AMD processors. TLP is typically available in your distribution repositories.

System components

Quiet fans

PWM fans are the best option for cooling as the motherboard can control the speed based on the case temperature. These have 4-pin connectors that will appear similar to the header for the CPU fan and may come with rubber mounting dampers which are highly recommended. Ensure the motherboard supports a 4 pin chassis fan before purchasing. The BIOS usually has options to select 'silent' operation where the chassis fan(s) may not spin up until needed.

Another option is to add variable resistors to the fan circuit, altering the voltage supplied to your fans. Normal fans runs at 12V, but by lowering the voltage to 7V you will get lower RPM's and thus quieter fans at the cost of air throughput.

CPU coolers in modern processors (c2014) are typically quiet and no special attention is required.

Quiet and/or adaptive power supplies units (PSU) can also help reduce noise by a considerable degree. There are some premium PSUs that just use a heatsink for cooling, and thus run totally silent. However, they don't do much for the cooling of your case! A better solution are high efficiency PSUs (80 Plus Gold) or a pico-PSU and choose a PSU with a rating closest to your computer usage. It is highly recommended that a power meter is used to check that you will not exceed the supply rating of the PSU.

CPU choice

One of the good things about Myth is that 90% of the common functions don't require a powerful CPU at all, so you can often pick and choose the CPU that runs at the lowest power and heat output.

Intel Processors

Modern Haswell era Intel processors are handled by the kernel p-state driver and have multiple sleep states (C1 to C10) enabling low power and low heat CPUs. This is typically handled automatically but the BIOS settings should be checked to ensure the BIOS is able to put the processor into these C-states. Use powertop to check if these low power states are being reached.

If maximum power usage is a problem, the highest frequency of the processor can be capped in the BIOS resulting in a drop in maximum power draw. The processor will otherwise reduce frequency and voltage automatically. Otherwise, T versions of the Intel range are low power variants but may exhibit the same power draw at idle.

AMD Processors

If you have an AMD please add information in here.

Optical drives

A contributor to noise and vibration are optical drives running at 16x or 52x. To watch DVDs and play CDs you shouldn't need a drive faster than 1x DVD or 1xCD respectively. The DVD and CD specifications are written such that a DVD should playback video or video perfectly well at the drive's lowest available speed. Hence a drive with the lowest speed should be chosen as MythTV needs fast disc access is when ripping a CD or DVD. You may also want to experiment with hdparm, setcd or speedcontrol; All claim to be able to reduce the maximum speed of optical drives.

As of this edit there are no optical drives on the market that are specifically advertised as being quiet or having quietness as a feature. Some drives have "quiet" firmware/utilities available which will limit the speed to a more reasonable and less deafening level. Since almost all drives require that their firmware be upgraded using Windows or DOS you may run into difficulty attempting this method with a Linux based computer running MythTV. You do have the option of putting a drive into a Windows based computer, applying the firmware alteration, and then putting it back in your Linux based computer (a variation on this theme is to always have a FreeDOS bootable partition).

Chassis

Keeping all those cables tidy can do wonders for airflow within your case, and do away with the need for more fans. You can tie bundles of power cables together using zip ties, braiding or spiral wrap.

It is possible to soundproof your case with acoustic material. This is essentially sticky-backed foam that does a lot to absorb noise from inside the case, although you'll need a case with enough free space inside to accommodate its thickness. I've never tried this myself, but a lot of people swear by it. Lian Li and Zalman make some very pretty (and pretty expensive) cases fitted with this sort of anti-noise technology as standard, so those of you who want a big, quiet case might want to consider splashing out on those.

Furthermore you can uncouple the case mechanically from whatever is underneath it, or whatever it's underneath. Conducted noise which is then transferred by another device is a major component of the noise which a PC can put out — which explains the rubber mounts you can get for hard drives. They're good for noise, but bad for thermal conduction. (You do have a fan blowing directly on your hard drives, right?) Standing the chassis on a piece of carpet, or even better, underlay will cut down on transmitted noise through the floorboards, plasterboard etc.

For more information on keeping your HTPC (and PCs in general) quiet the website Silent PC Review has some excellent guides, reviews and forums to provide you with all the details you need. Their recommended hardware section contains lots of hard numbers.

Useful Links

SilentPC Review - Contains reviews and guides on quiet PC cases, fans and components.

See also