Cool, low power, underclocked system. Is my idea workable?

[mikepn]

Hi all,
I'm new to the forum, and in general to silent computers.
Basically, I want to create a computer to do standard, low-power stuff, specifically: email, internet surfing, word processing, and watching DVD's. I currently have normal, loud computers for the purpose of more intense stuff (programming, massive number crunching, games, video editing, etc), but that's not the main task of the computer.
Also, the low power computer does not need to hold any media (music, videos, etc), so it doesn't require much disk space.

So, here's my basic setup idea:
*AMD Semptron or other cheap processor (a 2400+ costs around $60 from NewEgg at the moment)
*Some motherboard that supports overclocking (in my case, underclocking). I'd prefer MicroATX
*Around 512MB RAM (or maybe just 256MB, depending on the OS I decide to install)
*One 1GB flash drive for the OS and programs, one 1GB flash drive for documents, and one 512MB flash drive to serve as swap memory, if the OS should use swap memory (I'm no Linux expert yet, so I don't know what the standard Linux swap memory setup is. I guess Knoppix can work without it, since it can run without any hard disks or writable storage)
*One big old fat heat sink like the Scythe SCNJ-1000.
*Some quite power supply, like the Seasonic SS-200SFD or something fanless maybe.

I would then underclock the processor to about half it's speed (just a couple years ago, people would have killed for a processor that fast).

So, first of all, does this sound workable at all? I've heard that Semptron 64's don't have a locked multiplier (or it can be unlocked) and thus underclocked.

Second, flash drives technically only allow between 100,000 and 1,000,000 read/write opperations before the break. Has anyone used a flash drive as a hard drive? Has it burned out yet? (Note: this is the reason I'd have a seperate drive as my swap drive, since that would suffer from more common reads and writes, so it would be nice to lose nothing at all once it dies).

Does anyone know how much power such a system would use?

Does anyone know how much power a cheap laptop uses?

What about taking apart a laptop with a Pentium-M (or Celeron-M), and installing a bigger heat sink (thus allowing for a smaller fan)? Such computers have no power supply, and thus no power supply fan. Except for the hard drive and CPU/motherboard fan, they don't make a whisper. This report: http://www.crhc.uiuc.edu/~mahesri/class ... 497yyz.pdf claims that the tested laptop used 26 watts under full load (with a monitor).

I guess this leads into my next question... Can one buy laptop parts (mother board, CPU, etc) for reasonable prices? Or would it be cheaper to buy a whole system and take it apart?

Any thoughts would be nice.

I'd say my main goal is to build a low power system. Quiet comes much easier when the system is low power.

[Bitter Jitter]

Would a notebook drive not be an easier and comparable option to using flash drives? The single platter 40Gb drives from Samsung and Western Digital are very quiet and can be enclosed to make them silent. The cost and difficulty of a flash based systems seem too high compared to the difference in acoustics which is basically non if you use the right hard drive and mount it correctly.

The Semprons are equally as good as a Pentium M if set up properly. If you underclock down to 1000Mhz or 800Mhz you should be able to run the CPU passively.

Pay special attention to the motherboard, an Nforce 3 or 4 will require more power than a VIA, ATI, SIS or ULI. Also PCI express seems to require more power than an AGP based board. The differences are small but it all helps, less heat makes quiet easier.

[IsaacKuo]

I have quite a bit of experience putting together silent PCs for such tasks on the cheap. By cheap, I mean REALLY REALLY cheap. I mean spending ~0$ cheap, except for the hard drive.

First, the CPU: I've gone as low as a 433mhz Celeron and gotten smooth video playback out of it. Any Pentium III or Celeron faster than that will do nicely. Using my flipped PSU fan ducting techniques, I have had 100% success using STOCK CPU HEATSINKS with the fans removed. That leaves just one 5volted 80mm fan in the system. Cherry-picking that 80mm fan results in silent operation.

Second, the RAM: With Linux, I get acceptable performance with as little as 64megs of RAM, but that assumes a lightweight window manager. With Windows 98, I've gone as low as 32megs of RAM, but it thrashes. I'd recommend about 128-192megs of RAM; maybe 256megs of RAM for a heavier Linux distribution (like Mepis).

Last, the hard drive: The hard drive is an interesting issue. This is the one area where I have to spend money to acheive true silence. I haven't used flash memory yet, because I just can't justify the cost. For less money, I can get a very quiet 2.5" drive along with the materials to make one of my homebrew 2.5" drive enclosures. The resulting drive is SILENT, and it has 40gigs of capacity.

[dragmor]

So, first of all, does this sound workable at all? I've heard that Semptron 64's don't have a locked multiplier (or it can be unlocked) and thus underclocked.

You need a Sempron 3000+ or higher to get CnQ which will get you the unlocked mulitplier. The 90nm semprons use a lot less power than the socket A chips.

I think your best bet would be a Sempron 3000+ with a Nvidia 6100 Motherboard (passive cooling, onboard video, sound, etc) underclock/volt to [email protected] and maybe drop the memory from 200 to 100 and see if you can undervolt that as well.

[frostedflakes]

You can get Linux distributions designed specifically for no-moving-parts (a.k.a. fanless and flash-based) PCs. Damn Small Linux (DSL) comes to mind immediately. The frugal install requires only 50MB of disk space and loads itself onto a software RAMdisk during bootup (to prevent wear and tear on the permanent flash storage). It's nothing special, but has a nice interface and all the basic apps (Firefox for the web, OpenOffice for word processing, etc.). Really impressive considering how little disk space the OS uses.

If you can find an old Celeron in the 500-700MHz range, I'd grab one of those. Of course a Sempron would work, but is probably overkill for what you need (even when underclocked). The low-speed Coppermine Celerons were very power friendly. IIRC the 533MHz 1.5V Celerons had a TDP of around 12w.

EDIT: You might also consider something like this. The board is flex-ITX, but will fit in a micro-ATX or ATX case.

[alleycat]

You haven't mentioned that you want a fanless system, so I'll assume you're happy to have some sort of forced-air circulation. This makes life a lot easier, and your choice of CPU isn't so critical. The Sempron/Ninja combo seems like a good idea, as you should only need a bare minimum of air movement to keep things reasonably cool. I wouldn't bother with underclocking, but undervolting or at least enabling CnQ would be an advantage.

What PSU you get will determine your cooling strategy. If you're using a fanned PSU to exhaust the heat, you'll need to make sure the CPU HS is in the airflow path, and that the fan doesn't increase speed with the increased heat load. The other alternative is, as you mentioned, a fanless PSU. In this situation you could use an 80mm Nexus exhaust fan, which would provide the airflow through the HS, as well as move a bit of air past the underside of the fanless PSU. You'd then be able to tweak it for the absolute minimum airflow that you need. You won't be able to hear it. Really.

I've always been fascinated by the idea of using IDE CF cards for storage, especially the OS, despite whatever drawbacks others inevitably point out. I wouldn't use one for swap, though. You'll just need to make sure that you set up your OS so that it doesn't use swap. I haven't tried any of this, but I've heard that people have done it; you'll need to look around. Some people will argue that you MUST have swap, but I personally don't believe this, especially if you've got plenty of RAM. One workaround I've seen was to create a ramdrive and put your swap there, but to me that just seems silly.

And by the way...
Welcome to SPCR!

[ronrem]

The late model Sempron 2800 has Cool N Quiet and 64 bit ability-and is cheap. Coolmax has a PSU with a 140 mm 3-speed Yate Loon,1000 rpm min. A Sempron 2800 with a Ninja or NCU 2005 heatlane right next to that 140 won't need any other cooling. And that's without underclocing. Cool N Quiet or Crystal CPU is basically auto-underclock,in that if the power demand is low,the cpu runs slower +cooler. Cool N Quiet often will not work if you underclock/undervolt. I'd rather have the power when wanted even if she's usually running at the lowest CnQ clock. I tend to think a 7200 rpm SATA Spinpoint is sweet for silence+price+speed. A much slower,more expensive notebook HD is a bit quieter but not enough. Get a spinpoint,heatsink it + suspend it.

I have a Powercolor Radeon 9200 ViVO which is passive. Your quiet video puter may as well do vid capture,and 754 mobos are AGP.

[Filias Cupio]

Yes, Linux is able to use swap. You dedicate a disk partition (or several) to swap.

I don't think there is any point in getting flash memory for swap. Swap is just virtual RAM, and given that flash memory is about the same price as RAM, you're better off with real RAM - it is faster, doesn't require any setup, doesn't wear out. The advantage of flash is that it is persistent, which is a feature you don't need for swap memory.