Underclocking for a Quiet Machine? 62
The Fun Guy writes "I'm running a PIII 600MHz, which I'm thinking of upgrading. If I could get rid of the fan and run more quietly, I'd love to. I run office-type apps, so I don't need the fastest processor around, but I also run d.net, so I'm constantly pegged at 100% usage. Aside from the obvious fact that your CPU is running slower than the listed speed, is there any downside to buying, say, a 1.8GHz chip and running it at 900MHz without the fan? Any experience or FAQ's to share on this?" We've covered this topic several
times
before, with some good feedback, however most of the approaches don't discuss the use of underclocking to accomplish this, although one common suggestion from the comments is to use a non-Intel processor, if you can. Have any of you tried underclocking your CPU to allow it to run silently? How far do you need to underclock a processor in order to enable it to run without a fan?
My setup works (Score:4, Funny)
Fuck that high falooting stuff. There's some halfassed word processor that'll work just fine for this beast. And I'm not joking about this shit.
Water cooling, honey (Score:2, Interesting)
Since I run an Athlon XP machine with lots of hot hard-ware in it, I found that underclocking to take a few degrees off of the CPU temperature was futile. It made about 10 degrees F of difference with the fan still on, and that just didn't seem like enough to risk my investment by running it without any active cooling.
So, I went with a water cooling solution. Although I decided to roll my own system using components available over the Internet, there are several cases [hardocp.com] that come with water cooling built in. Some of them don't even require a water pump, which is a super big plus if need absolutely zero noise, like me. I've been quite satisfied with mine so far, however, your milage may vary.
The Silent PC (Score:4, Informative)
http://home.swipnet.se/tr/silence.html [swipnet.se]
I say take a break from the computer room, or use a laptop, or maybe turn the computer OFF every once in a while if you don't like the noise, but hey, to each his/her own.
Underclocking won't help very much... (Score:1, Informative)
The basic equation you'll run into is that for a given amount of processing power the cpu is going to be releasing a given amount of heat. If that heat is not dissipated it'll build up destructively.
The last processor I saw without a fan was a PII 300, and that had a heatsink twice as large as a normal fan heatsink situated directly below the power supply - which meant that it got a good deal of active cooling.
In order to effectively cool a modern processer (which does put out less heat per clock cycle than older processors, but not by much) you cannot just slap a large heatsink on it, slow it down, and expect it to have enough cooling.
In short, the only downside other than having a slower computer is that it won't work. A 1.8GHz processor running at 900MHz is going to let off as much heat as a processor in the same family rated at 900MHz, which surely needs cooling.
The 1.8GHz processor is letting off more heat than the 900MHz. The reason you can use the same heatsink and fan is that the heatsink and fan are overrated for the 900MHz, but not so much that the fan is not required.
Lastly, current processors are pipelined dynamic machines, meaning that they have a range of clock speeds in which their output will be valid. Too slow and they stop working, too fast and they stop working. You're generally safe underclocking a processor whose same die includes processors at the lower speed, but be careful, since higher speed variants generally have some small die changes which are not great enough to tell anyone, but do affect the range.
This field (thermal dynamics) is rife with documentation and resources. You should be able to calculate the heat output of the processor and determine the correct sizing heatsink. Don't be surprised if you find it requires a passive heatsink size of greater than 81 square inches, with a surface area significantly larger...
-Adam
Re:Underclocking won't help very much... (Score:3, Informative)
So in general, it may be possible to underclock the
Informative?? Not...! (Score:5, Informative)
Umm, yeah, right, you don't know much about CPU design these days do you?
Discounting the above, my own real world experience has been that Intel CPU's can typically eliminate the fan with a 20-30% underclock. AMD is almost not worth it needing at least 50% underclock. Also you NEED the biggest darn heatsink you can find and I strongly recommend active heat monitoring and some sort of automatic powersaving idle/shutdown/whatever if you leave the machine alone for long periods. Somebody mentioned large heat-sinks being close to the power-supply fan intake, this is a good idea and can be accomplished by using a duct (and possibly some judicious cutting) if your power supply vents are inconveniently situated.
Re:Informative?? Not...! (Score:2)
Fanless CPU (Score:2)
done it with some old CPU's (Score:3, Informative)
At this point it ran cool, but it wasn't quiet at all. The hard drive was the newest component and it was friggin loud. I took that out and made an LRP type floppy and now I sleep next to the thing.
This used to be a workstation that I woke me up from across the room even when I placed it behind a bookcase. But the real moral here is that you need to get rid of that hard drive, even if it goes to sleep quickly the thing can wake you up when it starts spinning to record some log or whatnot. I also got rid of of extra stuff like the power supply cover and tapedrive and what not that just weren't good for airflow. In terms of time spent the router would have been cheaper, but it was fun and the thing is flexible.
I think that If I ever build a fast machine that needs to be on all the time I'll just find a way to hang it outside my double pane windows. Long cables...
Re:done it with some old CPU's (Score:3, Funny)
No offense, dude, but how's your love life?
There is no such thing as a free lunch. (Score:1, Informative)
/Pedro
Re:There is no such thing as a free lunch. (Score:1)
/Pedro
Not always true... (Score:2)
Re:Not always true... (Score:1)
/Pedro
Re:Not always true... (Score:2)
My experience (older hardware) (Score:3, Informative)
I got a 300MHz K6-2. It went in fine, and I started it out around 200MHz. But my network card (3COM 3C905-tx) freaked out. It dropped packets like crazy and wouldn't even hold a link to my switch for more than a second at a time. Uncerclocking even more made the situation a little better, but I could never get the network card completely stable.
Eventually, though, I *was* running the K6-2 without any heatsink whatsoever, and it only got warm to the touch. This was around 100MHz.
That was even running it at 2.5V, when it only required 2.2V even at 300MHz. Since it was underclocked, it would have probably run below 2.2V, which would have been far cooler than what I had.
Unfortunately, my experiment came to a rather spectacular end when I decided to put the heatsink back on while the system was on. The heatsink clip paid a visit to some pins of a power transistor nearby on the motherboard. Let's just say that sensitive digital equipment like a motherboard isn't supposed to make sparks. Surprisingly, the motherboard was fine - but the cpu was toast. I just went back to using the P90, a little miffed about losing $15, but otherwise fine.
Re:My experience (older hardware) (Score:1)
Don't forget the power supply (Score:2)
Granted, I'm not running super-high end systems, but I doubt the cooling requirements of the newest AMD and Intel chips are such that they require a fan to run so fast that it's louder than the power supply, especially if you buy a decent quality one.
If you have a way of monitoring temperature of your processor and motherboard, you *could* play around by reducing the voltages to the fans (both cpu + ps), to slow them down a bit. This might cut the noise to an acceptable level. Certainly not something I'd consider doing on a system that's important to you in any way, though!
Of course, if you're a *real* geek, you have your big system sitting in a server room somewhere and connect to it with an xterm sitting on your desk!
No Problem. (Score:1)
Im sure you could run your 1.8 ghz at 900mhz with no issues other than less performace because of the lowered clock speed but thats already expected. you may beable to get away with a 1Ghz or more depending on the quality of HS.
if you need the speed or gonna over clock, water cooling is the way to go. but for your needs just find a nice HS.
easier way... (Score:5, Interesting)
- cpu fan
- disk drive
- case fan
- video card fan
- power supply fan
- cd spinning
Ok, so my way of solving the problem doesn't involve underclocking, but it works better:I put the computer in another room.
Get a good monitor cable (one with ferrite cores) and a keyboard extension cable and run them through a wall to the computer in another room. Now *that* is quiet. And it costs maybe $50.
Now to be honest, that's not exactly my setup. I actually have a KVM switch and hook to several computers in the next room. I have a nice quiet bedroom with a keyboard, monitor, speakers and a usb KVM switch. If you look at http://www.belkin.com you'll find kvm switches that switch audio too.
Re:easier way... (Score:1)
Not only is it quiet, it really impresses the chicks...
:-)
My theory (Score:3, Interesting)
I haven't actually tried it, and I'm sure some joker who doesn't know what he is talking about will chime in here and pose as an engeneer and say it can't be done, but I really thing this will work.
You won't be able to lower the voltage much, because you'll need to meet a certain minimal signal level. OTOH, less clock means less noise, and every little bit helps.
Also consider using a notebook HDD. Quieter and cooler.
Good luck!
-Peter
Underclocking (Score:4, Informative)
You could also buy a CPU that can run at 933MHz without a fan [siliconacoustics.com], the VIA C3. It's pretty good, but the FPU is quite anemic. Personally, I think it's a small price to pay for some peace and quiet.
Ian
Ouch! (Score:1)
A two gigahertz P4 can comsume 100watts. As much as a light bulb. Ouch!
P4 power consumption [sandpile.org]
do this... (Score:2)
As for the HDD, I'd suggest a Seagate Barracuda ATA IV, they are almost completely silent.
Now get a PSU with a speed-controllable fan (enermax has a few) or a temperature controlled fan (Antec SmartPower) and you're set, almost complete silence.
Redundant (Score:5, Informative)
And yes, the chimney effect of the tube makes it feel like there is a fan blowing hot air, just like the G4 cube.
Good coper heatsink (Score:2, Informative)
On a side note, that delta is one of the loudest SOB's out there, but it kept it mighty cool back when I had my machine foolishly OVERclocked, and didn't realize that for what I was doing 1Ghz was plenty fast.
Would you gaining anything? (Score:1)
There are always sound-deadening cabinets... (Score:4, Interesting)
I've seen a huge amount of discussion over the past few years about doing things to computer cases to deaden sound. Now, one person in this discussion started thinking outside the box, talking about his putting the computer into the next room and running cables through the wall -- effective to some extent, but absolute hell when you have to put a CD-ROM into the drive, don'tcha think...
What I've been looking to do is build a proper sound-controlled cabinet for my computers. It would be an enclosed cabinet with doors, fans (ducted at inflow and outflow ports with sound-proofing material) to ensure enough air flow to keep internal temps down, built-in power distribution, built-in Ethernet (I have a 24-port 100-base T hub), and sound-sealed cable ports for the KVM switch and external connections.
Some design points:
The cabinet needs to be deep enough so that the system units will have adequate front and rear clearance for airflow. Experiments with standard cases tells me that you need at least four inches rear clearance and six inches front clearance. The extra clearance in the front is dictated by CD-ROM and DVD-ROM drives, so that the door of your cabinet doesn't interfere with the CD/DVD-ROM tray. Given that the deepest cases are about 20 inches, that means you need an inside depth of 20 + 4 + 6 = 30 inches. Plan on 36 inches of depth for the outside dimension
Your primary sound barrier will be dense material, such as plywood. If you can get birch plywood, this will give you better sound control because of the increased density of the wood. It's tempting to go very thick, but 5/8 inch should be plenty good. Consider using 1x6 for the framing, and be sure the plywood is braced at least every 18 inches with framing.
Most acoustic treatments will require about two inches of depth in order to be effective across the "band of annoyance" (200 Hz to 4 kHz). Thick-pile carpeting (make sure it's flame-retardant!) can be surprisingly effective, and cheap when purchased as end-rolls or remenants. Fiberglass batting and rock wool are also effective, although the stuff is tricky to work with safely. For the sides and the rear wall, standard acoustic tile or ceiling panels can be effective. For ducts, the goal is traverse absorption, so materials like acoustic tile may not be appropriate as they tend to best absorb sound hitting the tiles perpendicular to the surface.
Design the airflow so that air deflects around sound baffles; this prevents direct ray-path propagation of unwanted noise. For example, an air intake can be done by using a front floor-level opening, a baffle panel of burlap-covered 1/4-inch plywood, and a 5/8-inch plywood shelf for the computers that stops six inches from the front of your cabinet. This design directs the airflow to the front of the computers, which from most cases seems to be the most desirable. A similar baffle system at the top of the cabinet can serve to exhaust air, again using baffle panels to break up any direct ray paths.
Any air-motion equipment should be suitably baffled as well. Large low-RPM fans work better than small high-RPM fans.
Finally, cable ports need to be sealed acoustically. Consider rubber gasket material, or the "tube foam" you can find at some fabric shops.
For my prototype, I'm using a rack cabinet I got at an auction last year. The metal skins (including the top one) is replaced by 5/8-inch plywood, faced on the inside with long-nap carpeting. The air intake at the bottom of the cabinet uses exactly the baffling technique I described above, using burlap soaked in fire retardant. Air exhaust is still a problem. Cables go through two slots in the back of the cabinet. The "door" is currently a removable panel of carpet-faced plywood, but I have designed a quad-door arrangement - this lets me get access to the CD-ROM drives without opening the entire front, yet provides for service access easily.
Temperature monitoring is a bit of a problem right now, a problem I hope to solved via eBay.
When I have more, I'll put it on my Web site and let you all know about it.
(One thing: I'm a bachelor, so I don't have a wife to worry about. Your mileage may indeed vary.)
Underclocking AMD is fine (Score:1)
From http://home.swipnet.se/tr/solutions.html
apple cube (Score:1)
Re:apple cube (Score:2)
That's half the magic behind the Cube's size and silence.
I'd love to see a third party create fanless power supplies that are plug-and-play replacements for the PC world.
Personal Experience (Score:3, Interesting)
Since performance was not an issue (about 10 clients).
I decided to underclock the processor (a very old CyrixPR166). The right clock speed would have been 133, but I clocked it to 100.
This was a zero maintenance server, in fact it ran for about two years without a single problem.
After two years, it needed an HD upgrade, and I opened it, to insert a new HD. To my surprise, the CPU fan broken, and in fact, from the dust I guess it didn't work for some months, but still the CPU had no temperature problems.
What's the moral of this story? Don't use the muscles (Mhz) if you don't need to!
Pentium 4 is the answer (Score:2)
Don't worry about any underclocking. Just run the chip as is with as much cooling as you feel like it and it will automatically adjust it's speed to suit the conditions.
Note. I will take zero responsibility for any direct or indirect damage to your system that results from the advice above. It should work but you can't tell for sure until you try..
Celeron with 0.13 process is runs w/o fan (Score:1)
"First off, I'd like to say that Celeron
I bought a 1GHz
So then I tried it at the rated 1GHz, not expecting it to even boot. But absolutely no problems here either. Top temp nudged up to ~38C, and of course performance was vastly improved. Just in case you think the thermistor is lying, I did the "finger test", which suggested <40C."
The 0.13 celeron is the one made with the PIII process and is sometimes called the Celeron II. It's a good chip. I personally have one these 800Mhz chips overclocked to 1066Mhz, using the stock Intel fan and heatsink. It barely gets warm.
External power supply? (Score:1)
It would be great to be able to connect a small power connector like a laptop. How practical would this be?
I am no electrical engineer, but I don't see why this isn't feasible. Seeing as it would be outside the case, it could be covered in heat sinks, cooling fins, not needing a cooling fan at all. Might get a little hot, but at least it'd be silent.
Come on. Someone here has to be able to build one.
reduced fan speed (Score:1)
Re:reduced fan speed (Score:1)
Power Supply Fan likely to be largest noise source (Score:1)