This is the first computer I have ever built.
Warning: the beauty of the craftmanship was not my objective at any point. If you are sensitive to shocking images of mistreated case, do not look any further (you may avoid some nightmares).
- HTPC and web surfing use
- runs 64-bit Linux
- low power consumption
- air cooled but very quiet
- reliable and care-free hardware
I thought that I can make it almost silent by choosing quiet components. All I have to do is to connect them together and turn it on. Right?
- Case: Antec SOLO
- CPU: AMD Athlon 64 3500+ (65nm, 45W TDP!)
- CPU cooler: Arctic Cooling Freezer 64 Pro
- PSU: Silverstone SST-ST30NF-GM PCI-E (Fanless)
- MOBO: Asus M2NPV-VM + Asus S/PDIF card
- Memory: Kingston 1024MB 667MHZ DDR2 NON-ECC DIMM
- HDD: Samsung Spinpoint 320GB T166 7200RPM SATA
- Optical: Samsung SH-S182D/BEBE Super-WriteMaster
- TV Tuner: Hauppauge WinTV-HVR 1300
To my surprise it was relatively quiet but nowhere near to what I wanted. The ambient noise in my living room is very low. I had to do some modding to improve acoustics.
Added while modding:
- American Acoustics SilencePack
- Noctua NF-S12-1200
- Noctua NF-S12-800
- Coolink Mainboard Silencer
- Scythe Quiet Drive
The MOBO is clearly HTPC oriented but for some reason the S/PDIF connector had to be ordered separately.
Ain't this PSU a freaking' beauty?
Freezer is amazingly good for a budget cooler. The fan is relatively quiet in low/medium speed but still too noisy for me.
I thought that I could get rid of the extra noise by adding an acoustic layer to the case. There was already a thin layer but it clearly wasn't enough. Also the Antec Tricool fan included in the case was terribly noisy.
At this point I realized that there wasn't any easy way to keep this thing quiet without compromising the cooling. I decided to re-design the air flow and to enhance the HDD mount. The SOLO case has elastic cords for HDD built in and the Spinpoint drive I had is a quiet one (for 7200 RPM drive), but the noise was still way too much to me.
The air flow was originally quite bad: CPU cooler was blowing all available air to CPU heat sink only and the tiny GPU heat sink below it felt really hot. The heat from the GPU sink went directly up to the CPU sink base, thus making the CPU cooling less efficient. Hot air accumulated to top of the case, around the PSU, making sure it stayed hot. The fan grill and intake filters lowered the air flow and the fans had to compensate it with extra speed.
Before ending up with the final design, I did several experiments and measurements, finding solutions that were noisy and/or compromised the cooling.
My enhancements were based on common sense and basics of physics:
- Hot air tends to rise up and must be able to escape from the top.
- Cool air is available near the floor and must be taken in from there.
- All obstacles of air flow must be removed.
- The air should be blown through the heat sinks and then directly out.
- The air flow inside the case must be directed to cool all MOBO components.
- Some air must flow around the HDD to keep it cool.
- Number of fans must be low and they must use minimal speed.
- The fans must be sound-isolated from the case.
In contemporary DELL office tower cases, the number of fans is quite low because the air flow is desinged to fully utilize each fan: they all serve multiple purposes. I applied the same idea to my design: one fan to cool both heat sinks and to get rid of the air heated there and another one to take cool air from the bottom and to direct it to MOBO components (and for the use of the heat sink fan).
To ease the air flow I cut off the fan grill and detached the intake filters. To direct the warm air from the heat sinks out of the case, I made a simple air tunnel using cardboard box of the TV tuner card. For letting the air out at the top of the case, I drilled a row of holes.
I replaced the noisy fans with Noctuas. I know there are some contradictory claims on them but in my design they obviously do very well. There are two 12cm fans, 1200 RPM model and 800 RPM model. They look identical outside but behave very differently. The 1200 RPM model is a bit noisy, even with lower RPM while the 800 RPM model is very quiet except for the top speed.
The 800 RPM model is now my heat sink fan, thermally controlled by the MOBO. It hangs behind the sinks tied by elastic cord. I wouldn't have bought the 1200 RPM model if I would have known it was so noisy (don't get me wrong: is a lot quieter than the fans in general). To make it silent, I connected it in series with the Ultra Low Noise Adapters of both of the fans. If I calculated correctly, it now gets about 3 volts but it still starts just fine and I feel the blow of air. As the voltage range specified for it is 4-13V, this must be now that "undervolting" you guys keep talking about? The low volume of intake fan is also intentional because then some air comes in also from the front, to cool the HDD.
Now comes the ugly part: a new intake hole to the bottom. The intake fan is not attached at all. It just sits in a block of foam cut in shape.
The hole doesn't look anyhow nice but thenagain, it is facing the floor. In case I need to build another computer some day, I'll buy a Dremel.
The Noctua U.L.N.A cords (short extensions with a resistor) connected in series. Omitted filters.
Getting rid of the fan grill.
The tunnel for directing the air out.
I replaced the original GPU heat sink with Coolink Mainboard Silencer in order to improve the cooling. The heat sink fan is lowered enough to blow some air through it.
At both sides of the case, a row of holes releases hot air rising from the MOBO and from the PSU.
As the fan noise was now practically killed, all I heard was the HDD noise. Scythe Quiet Drive lowers it down very well. Antec case elastic cords help to remove rest of the vibrations and finally the acoustic layers and the sturdy steel cover of the case make it almost silent.
The HDD led is detached from the filter mount and is a bit dim outside. That is a plus because by default it was so bright it disturbed me.
The nasty looking back end remains hidden. Outside it looks just like any Antec SOLO computer.
The cooling works as expected. At normal (relatively low) load, with heat sink fan speed below 500 RPM, the CPU temperature is at 45 C and MOBO at 35 C. The GPU heat sink feels warm but not hot and the HDD case is barely warm.
When inserting a DVD to play I noticed that the optical drive was extremely noisy. The noise comes from excessive spinning speed. The spinning is fortunately possible to control by SW: I just let the Linux to send a command whenever a DVD is detected in the drive: hdparm -E 2 /dev/cdrom, meaning: "use no more than double speed with the current disk".
Now I'm happy with the sound. To hear it, I must wait a silent moment; no wind or rain outside, no traffic anywhere near, no other electronic devices turned on and no cat purring in the same room. Then I put my ear close enough to touch the case and concentrate a while and the noise becomes audible: it isn't totally silent! Extreme HDD seeking can be audible upto 20 inches away from the case. Never mind, it is very quiet and that's enough for me.