I have read this site for several months and in the process made improvements to two older PCs which now emit a bearable amount of noise as an HTPC and a computer at my Mom's.

But for this new project, I started from scratch with all off-the-shelf-products, no-mods and put together the quiestet possible computer.

iStyle Case (white)
P4 2.4C 800mhz w/NCU-1000 (no fan)
SilentMaxx Prosilence 350
AOpen AX4SPE-N
2x256 Corsaid RAM 800mhz
80g Barracuda in a SmartDrive2002
Zip-CDR (old)
Matrox G450 (old)
92mm Zalman case fan with the slowdown resister attached, now at 1500RPM driving air out the back of the case.

There is no noise with this computer except for the one 92mm fan; the barracuda is totally inaudible. For a week, the computer has now sat comfortably in the bedroom. I can hear that the single fan whirring... just barely. During the day, I have to see if the lights in the front of the case are on because it is totally indisguishable with other sounds in the room. It is quiter now than my Toshiba laptop.

Heat is a problem. I use it only for WWW, email, IM, word processing, cd-burning, some layout, photos.... Nothing stresses this computer and it hasn't yet crashed/frozen once out of windows. Silentek reports:

SYS is 30-45C
CPU is 40-70C
CPU KERNAL is 60-80C

It is serious but the computer is running normally. If the P4 is throttling to lower speeds automatically then that is fine with me. I had some problems when the computer failed to post at Vcore 1.35 so now Vcore is set to 1.40. If heat gets worse, I might try better heat tranfer goop and bouncing the zalman fan back up to 2000RPM or replacing it with a better case fan.

In an case, I am extremely happy, the computer is nearly silent, it stays on all day and is incredibly fast. If anyone has suggestions or questions. Let me know. I know I learned a lot from this site.

Sounds like a great setup you have there, and money doesn't seem to have been too much of an issue either, not with the NCU-1000 and the Prosilence that has been used.

My only issue would be with the 80Gb Barracuda within the SilentDrive (whichever barracuda model it is, it's bound to be a 7,200rpm model) and the SilentDrive enclosures aren't best suited to drives that spin at such speed and generate that much heat.

Check out the specifications table here:

http://www.molex.com/cgi-bin/bv/molex/i ... drive.html

The only reason I mention this is because I too have a SilentDrive enclosure, but I'm using a Seagate U5 (5,400rpm) within and these drives aren't speedy nor generate too much heat. Even so, the heat label that came supplied with SilentDrive has reached at least 50°C which is the upper boundry I'd like to run my drives at, and my SMART temperatures support this also. See if you can discover the HardDrive temps to see if their running a little on the hot side.

Just a thought.

Oh wait, the HD silencer is the _Smart_Drive2002 which as far as I know is safe for a 7200rpm drive. It is the solid black metal with copper plates on the inside. I don't have temps of the drive but I seems to work so far.

Flip,

Oops....you're right...my mistake

I always seem to get those two enclosures mixed up.

Flip,

Very impressive setup. Congratulations on your achievement!

Congratulations Flip

What is a NCU-1000?

http://www.tsheatronics.co.jp/zen/engli ... 000_e.html

I've read in a review that it's not suitable mounted on a desktop case, since that will interfere will the heat dissipation through convection (top fins will block bottom fins). Not a problem with the iStyle, of course. But won't work in my ATC-600 *sigh*

First of all I must congratulate Flip to a great silent computer!
I do have a few concerns. Flip's computer (undervolted P4 2.4C) should give 57.6W at full speed. From what I have read and doing some guesses on the rather low airflow in the system you should be able to cool about 40-50W of CPU heat with the solution. So as long as CPU is max 75% you should do fine. If you push CPU harder for more than a few minutes you might end up with real high CPU temp. I guess that CPU throttling will automatically go down to 50% CPU speed and save you here. Still that means you are going with too high temps (from my point of view).

Yes, heat has been a major problem. I built the PC on one of the hottest days of the summer in New York and for a while I was having problems with post and with CPU-intensive processes. Now that it is cooler (around 20C), it is much easier to maintain the computer.

In the iStyle, the 92mm Zalman fan is drawing out air directly facing the NCU-1000 (because it is so tall), so this helps. Yesterday, I figured out how to program the fan speed in the BIOS, so the fan turns off when the computer cools at idle speeds and speeds up to a maximum of 1600RPM. A 92mm Papst is likely to be a good replacement here (although I think they tend to have a whiny high-pitched sound I don't like).

Originally I had some other unrelated IDE problems which also led to instability. Once I figured that out I can now get the P4 to start at vcore of only 1.25V. This has lowered the CPU temps tremendously. At startup, the CPU is about 35C and then goes up top maximum 55C under any normal operation for which I use this PC. This is stable for everyday use, so for me it is an acceptable temp. There is no sign of any CPU throttling at these temps.

When I push the CPU to max-load, I get closer to 70C, at which point the Aopen hardware monitor should shut down the PC. I have not had this happen. In any case, I believe the P4 is rated for up to 74C so there is no serious danger of hardware loss. If your work requires highly CPU-intensive work, then...

One way to get around this whole problem is to run with the side-cover off. When the case gets open airflow, I can turn off the case fan and the CPU still runs 10C cooler (at about 35-45C) even with CPU-intensive tasks. I did this for a while and it is perfectly acceptable (if you don't have pets). I have this PC under my desk, so I sometimes stuck my foot in the opened side of the case but with no sound it is a reasonable trade-off. If you had a large workarea, you might find other placements where the open-side is not a problem. If you don't mind running it this way, it is quite easy to use standard parts to run a completely passively cooled PC at current speeds.

The only thing is that this setup is expensive and I had to trade-off on getting other things, like an LCD screen, but it is feasible.

My new project is to try a CPU sharing program like BeTwin and run two simultaneous users on this one PC (with two sets of keyboards and monitors). This may actually turn out to be next most fruitful solution in terms of overall noise in the room.

Thanks to everyone for the comments.

Since you say that your temps drop 10C when you turn of the 92mm fan and open the case my guess is that your airflow in the case is far from optimal.
Mayby you should check what you can do to improve airflow?
Here is a few suggestions unless you have already done them:
Tie up any loos cables together.
Remove/replace flat cables (maybe remove floppy drive).
Increase air intake in the front och the case.
Make extra holes in the bottom front part of the chassi.
Add small ducting to CPU-cooler to increase airflow around it.

Nice to here about the 1.25V vcore, that really makes a big difference.

I definitely chose the iStyle purely for vanity. It is obviously not designed for optimal airflow. I don't have a floppy and don't have many loose cables (but now that I have seen what Ralf Hutter does with folding flat IDE cables, I'm going to have to do that some time). But the iStyle is steel/plastic and impossible to mod or cut directly.

The biggest problem is that with a single 1600RPM case fan (<30CFM), there is no airflow. For the most part, heat simply dissipates into or out of the case. I am sure that ducting would help, as would modding the case as to allow better flow of heat tranfer.

Can anyone recommend a good Pentium mobo (preferably mATX) that lets you undervolt and underclock? (I want to pair one up for a cool near-silent Office PC with my P4 2.4 Northwood, a new Heatlane Zen, and a Nexus NX-3500 120mm PSU). It should be a budget model (£50-£75) with onboard GFX and passive NB. I've been searching high and low for a few days, but the manufacturer spec's don't always give you enough info.

My #1 choice so far is a Gigabyte GA-81845GVM-RZ (£43), but it doesn't appear to let you change Vcore:
http://tw.giga-byte.com/MotherBoard/Products/Products_GA-8I845GV.htm

#2, a Gigabyte GA-8TRS300M, might:
http://tw.giga-byte.com/MotherBoard/Products/Products_GA-8TRS300M.htm

#3, a Asus P4R800-VM won't:
http://usa.asus.com/products/mb/socket478/p4r800-vm/overview.htm

The 120mm fan in the PSU will be the only one. There's good air intake at the front of the Gaming Bomb/Xpider. I'll be padding it out with acoustic insulation, and also wrapping it around a new Toshiba MK6022GAX (60GB, 5400rpm, 16MB) stuffed in a SilentDrive in the bottom of the case.

Shh! Is the name of the game...

AOpen's motherboards almost all appear to support undervolting. I wouldn't be too surprised if their latest offerings did as well.

Thanks - I'll have a look at all the Aopen boards.

I think I've hit a major stumbling block, though. It seems none of the cheaper boards (especially mATX) offer underclocking as an option. Only the more expensive enthusiast-overclocker boards have them.

For instance, this is the best one I've found far (£78):

http://tw.giga-byte.com/MotherBoard/Pro ... 20Pro2.htm

The manual implicitly states the Vcore range can be set from 0.8375 to 1.7600 - which is great. But, none of the 8IPE1000 mATX boards have the option, despite only being slightly cheaper (£63-£74).

To tell the truth, I'm not sure how reliable this undervolting/underclocking business will be. The idea is to reduce wattage heat output. I guess the P4 could just run stock with the Heatlane Zen and the first cheap Gigabyte board I mentioned.

It's starting to make less financial sense, if the board costs £80, needs a £14 ZM47J, and a £26 7000 GFX card (total £120). I could buy an A64-2800+ for that price, and splash out on an another K8V Deluxe for £75 to let that automatically undervolt to 1.275 and underclock to 800MHz for me...

It's not easy, this silent PC lark - is it?

Now, this one looks promising: micro ATX, onboard GFX...

Specification:
http://www.aopen.nl/products/mb/MX4GER.htm

Big mobo pic:
http://aopen.jp/products/mb/large/mx4ger-l.jpg

The "SilentTek" feature implies a Vcore range of 1.2 to 2.1, and the 1MHz stepping sounds good too. And it can all be done with Aopen utilities in Windows. Best of all is the price: just £50!

Can anyone verify the Vcore range is the same on all Aopen boards?

Now that you've been using the NCU-1000 for quite a while, what are you're thoughts? Any insights you'd like to share?

Well, I think the system has held up very well in the last year.

Aopen bios updates now allows me to stably lower the vcore on the P4 2.4C to 1.1V (reported as 1.06V in Silentek). It does a lot of divx encoding without any problems. Temp ranges from about 55-70 for varying levels of load. The pc remains on all the time.

I've replaced the 92mm Zalman with a Panaflo 92mm, which is even quieter. It is set to constant speed about 2/3 on the Zalman fanmate.

I had a problem with the Prosilence 350 (which has another thread), it was replaced by Silicon Accoustics (after some delay). That is the only problem I've had since I assembled the pc last summer.

I would do nearly everything the same way if I had to do it over again. I don't necessarily see that there has been any significant improvement in off-the-shelf air-cooling components over the 10 months (which is disappointing). Except for the Shuttle Zen, there doesn't seem to have been any compelling breakthroughs. Well, I'd probably go with a Samsung 160gig rather than the Seagate.