Hi all
 
question for you, please?
How do you keep your PC running silent? Mine has three big fans and they're set on silent mode from the BIOS but sometimes it gets noisy enough to bleed into my microphone (home studio here, I sing in front of the PC). Truth be told the case is a cheap one so it's not soundproofed. Do you think I should invest in a liquid cooled system for my CPU?
How do you make sure your PC stays quiet throughout your days' work?
Cheers!

A silent PC is the sum of all parts.

• Acoustically treated case (mostly helps against vibration noises).
• Quiet power-supply
• Over spec'd CPU cooler (cool CPU translates to quiet)
• Large low RPM Fans
• Quiet video card (if active cooled)
• Quiet drives

Liquid cooling can be noisy depending on the kind you get.
 
Here's what I did:Get a new case - I use Corsair Obsidian 550D cases. Fractal Design Define R5 is another good option, though not as well built IMO.Aftermarket fans/CPU cooler - I've moved to all Noctua fans and CPU cooling. Best. Decision. Ever. These are some amazing fans that are quiet.
SSD drives for absolute quiet - I only have 3 in my studio because they are still expensive on the larger format drives and my black drives are kind of noisy but not so much so that it's an issue.Get rid of the video card - Most modern CPU/Mobos have onboard graphics capable of handling up to 3 monitors at 1080p. Newer chips can handle up to 4K. If all you're doing is using a DAW and plugins, it's not going to take much processing to run graphics off the motherboard/processor.
Build/buy an isolation box - You're still going to get some noise from the computer. There is no getting around that. If the above isn't enough and you can't move the computer outside the room or in a closet, get an isolation box for it.

Quiet case - I'm using a Sonata IV by Antec and the case fan is set to low. I have an Asus MB and I let it overclock the CPU, but it didn't do anything drastic. Ran it for a couple days checking temperature and everything was fine. I don't have a video card, I'm using the intel video. This is a pretty quiet system. I used to mic guitar amps, but the emulations are so good now I no longer bother!

I have a Sonata II (I know its old!) by Antec.  It is very well built (read HEAVY!).  It works very quietly.  I have 1 120 GB SSD and two internal Hard Drives.  I use a Zalman CPU cooler on this.  If you have building for a while you know the name Zalman.  There are quieter ones now, but at the time I built my machine it was among the quieter coolers.
 
Mine is not silent, but it IS quiet.  I defer to Jim Roseberry as he builds them professionally and knows far more than I do about silencing PCs.

trtzbass
sometimes it gets noisy enough to bleed into my microphone 

That is a significant clue. Some cooling components are set to respond to temperatures at various locations in the computer. When things get hot the fans start turning faster. Usually, PSU fans are not running on demand, often case fans are as are CPU coolers. First thing to check is air flow around the vents to make sure nothing is blocked there. Presumably silent mode means slow and unchanging, so there is no reason why your case fans should make more or less noise.  Three fans in a case may be overkill, and losing one may help. Be sure you have a way to monitor CPU temp preferably with an automatic power down before messing with cooling settings, and look up safe temperatures for your CPU. A CPU can run at its rated temperature with little problem and there is no reason to run it much cooler than that. CPU cooling alteration is going to cost more if the cooler fan turns out to be the problem, but probably worth it. Water cooling may be better at cooling than direct conduction, but as noted above, may not be any quieter unless you can put the fan in another room. Typically a cooler with a large fan is better, and there is some room to adjust the response to temperature if there are settings on your board for that. 
 
Of course if the problem is that the sound is constant, and you only notice the bleed on quiet parts of the recording, then identifying a temporary cause of noise is a waste of time. 

Fanless here : zero noise !! all passif
 
Molten Muse +
 
http://www.moltenmusictec....co.uk/Muse-_p_16.html

Second the Fractal Design R5. It's easily the piece of my new DAW build I'm most impressed with. Cases have come a long way! The fans and the case treatment makes for a ridiculously quiet setup. 

patm300e
I have a Sonata II (I know its old!) by Antec.  It is very well built (read HEAVY!).  It works very quietly.  I have 1 120 GB SSD and two internal Hard Drives.  I use a Zalman CPU cooler on this.  If you have building for a while you know the name Zalman.  There are quieter ones now, but at the time I built my machine it was among the quieter coolers.
 
Mine is not silent, but it IS quiet.  I defer to Jim Roseberry as he builds them professionally and knows far more than I do about silencing PCs.

My previous computer was in a Sonata II, and I agree it was VERY quiet. Unfortunately, I kept breaking that !@#$ drive door. That aspect of the case is very poor in design. 

Zo
Fanless here : zero noise !! all passif
 
Molten Muse +
 
http://www.moltenmusictec....co.uk/Muse-_p_16.html

 
I have something like that (from another company that meanwhile is out of business) - but I TRULY LOVE IT.
 
It's all passive i.e. absolutely silent while giving superb performance. Sometimes it gets quite hot, but performance never suffered.  Used it for recordings, live shows, everything ... and when not in studio use, I actually move it to the office because it is quieter than the 2 laptops and seriously faster ...
 
Not cheap - cost about 2K with decent RAM and all SSD but well worth it.
 
EDIT:
Thanks, Zo for the link :-)
This must actually be the comany that took over from Rain Recording or whatever they were called. So what I got is http://www.moltenmusictechnology.co.uk/Muse_p_15.html  but in the much cooler brushed alloy looks.
Great to here that these things are still around because I'll get another when workload and money allow ...