Building a low-power pc

D

dterrors

I want to build a low-power network server linux pc.

Requirements:
1. Needs to be about as fast as a p2 400. Those fanlesss x86 procs
will probably do. Should I do a pentium "M" proc instead? Significant
power consumtion diff?
2. Needs to be big enough to hold a normal sized 3.5" ATA/IDE drive.
(Anyone recommend a low power drive of this size or do they all pretty
much consume the same power? I want it to be a seagate drive.)
3. Needs 128 ram.
4. Needs some usb ports.
5. I'd like it to be physically small too. ITX would work. If ITX is
significantly more than micro-atx then I'd be flexible...

Doesn't need much else. Crappy graphics capability. Doesn't need
sound. And am I correct that the power supply only draws as much power
as the pc needs?
 
D

Dave

I want to build a low-power network server linux pc.

Requirements:
1. Needs to be about as fast as a p2 400. Those fanlesss x86 procs
will probably do. Should I do a pentium "M" proc instead? Significant
power consumtion diff?

Not really.
2. Needs to be big enough to hold a normal sized 3.5" ATA/IDE drive.
(Anyone recommend a low power drive of this size or do they all pretty
much consume the same power? I want it to be a seagate drive.)

Depends on how you set it up. If you put it to sleep, it uses almost
nothing. It could be sleeping most of the time.
3. Needs 128 ram.
4. Needs some usb ports.
5. I'd like it to be physically small too. ITX would work. If ITX is
significantly more than micro-atx then I'd be flexible...

Look at a SFF system.
Doesn't need much else. Crappy graphics capability. Doesn't need
sound. And am I correct that the power supply only draws as much power
as the pc needs?

The power supply will draw as much as the PC needs, plus some, based on how
efficient it is. If the power supply is 70% efficient, then 70W power draw
by PC components will use 100W of wall socket power. That's because the
power supply must convert A/C to D/C, and no power supply is 100% efficient
at doing that. (some A/C power is wasted in the process) -Dave
 
K

kony

I want to build a low-power network server linux pc.

Didn't you ask about this already?
Requirements:
1. Needs to be about as fast as a p2 400. Those fanlesss x86 procs
will probably do. Should I do a pentium "M" proc instead? Significant
power consumtion diff?

Again, it's not so useful to try to compare to a particular
Pentium II MHz speed because these are different
architectures. You can only use the Pentium II MHz as a
gauge if you are using a Pentium II or nearly identical
architecture. It is simply non-applicable when considering
the more specialized, highly- low-power-optimized CPUs that
are ultra low power.

Instead you MUST factor for the specific demands placed on
the system. "network" tells us litte. "Server" a tiny bit
more... now we'd need to know what it's serving, and what
the server runs in the background, etc, etc.- ALL DETAILS of
what you're doing, not a random idea about what Pentium II
would do the job. I suspected you meant file server, and
this was already addressed last time so I have to wonder why
you didn't go ahead and build the system already?

I realize you may not understand why this is, and that's why
I told you last time. It's still true, that you have to
consider where your bottlenecks are to approximate what
class and speed of ultra-low-power CPU will suit your use.

A Pentium M is significantly faster than most other
alternatives, faster than a P-II 400, but also at full load
produces significantly more heat than the others too, so
determining the real need is very useful to target a thermal
load the system will bear, optimize for this fanless design
you mention above.

If you just want a random speculation without giving us more
details, you probably don't need a Pentium M for a
fileserver, but for a web server running scripts and a fair
load, you'd want one.


2. Needs to be big enough to hold a normal sized 3.5" ATA/IDE drive.


Ok, but only one? Servers often have some redundancy, like
a RAID1 if not RAID5 array.

(Anyone recommend a low power drive of this size or do they all pretty
much consume the same power? I want it to be a seagate drive.)

Supposedly some WD drives have a slight edge but not enough
to worry about, go ahead and get the Seagate since that's
what you want. The power differences will be minor, again
not enough to worry about. For lowest power usage you'd
have to go to a laptop drive or flash memory (and suffer the
inherantly lower write cycle limit and low capacity).

3. Needs 128 ram.

Not an issue, anything will.

4. Needs some usb ports.
5. I'd like it to be physically small too. ITX would work. If ITX is
significantly more than micro-atx then I'd be flexible...

Doesn't need much else. Crappy graphics capability. Doesn't need
sound. And am I correct that the power supply only draws as much power
as the pc needs?

Yes, a PSU only uses what the system needs plus a certain
percentage wasted power, usually around 30%. So for
example, a system as you described pulling 45W from the PSU,
would use closer to 64W total, plus consumptions of any aux.
parts like a monitor or additional connectivity like a
network switch.
 
P

Paul

I want to build a low-power network server linux pc.

Requirements:
1. Needs to be about as fast as a p2 400. Those fanlesss x86 procs
will probably do. Should I do a pentium "M" proc instead? Significant
power consumtion diff?
2. Needs to be big enough to hold a normal sized 3.5" ATA/IDE drive.
(Anyone recommend a low power drive of this size or do they all pretty
much consume the same power? I want it to be a seagate drive.)
3. Needs 128 ram.
4. Needs some usb ports.
5. I'd like it to be physically small too. ITX would work. If ITX is
significantly more than micro-atx then I'd be flexible...

Doesn't need much else. Crappy graphics capability. Doesn't need
sound. And am I correct that the power supply only draws as much power
as the pc needs?

This web page has a chart of some NAS systems.

http://www.tomsnetworking.com/nas/charts/index.html?chart=131

One of the NAS systems is big enough to hold a single disk
drive. It costs $149 at Newegg. At the end of the article,
some other devices are mentioned as well.

http://www.tomsnetworking.com/2006/...sm_g600_wireless_g_network_storage_enclosure/

Maybe you don't have to build anything. That unit is BYOD
(bring your own disk) so unlike many of the other units,
you aren't paying a bloated price for the disk. It has
decent power consumption characteristics, because it doesn't
use much of a processor. As for graphics, setup is via web
browser on another computer.

Paul
 
C

Chris Hill

I want to build a low-power network server linux pc.

Requirements:
1. Needs to be about as fast as a p2 400. Those fanlesss x86 procs
will probably do. Should I do a pentium "M" proc instead? Significant
power consumtion diff?
2. Needs to be big enough to hold a normal sized 3.5" ATA/IDE drive.
(Anyone recommend a low power drive of this size or do they all pretty
much consume the same power? I want it to be a seagate drive.)
3. Needs 128 ram.
4. Needs some usb ports.
5. I'd like it to be physically small too. ITX would work. If ITX is
significantly more than micro-atx then I'd be flexible...


If it is just network storage you're after, get an old dell desktop
p2/p3 machine and run freenas on it. The machine itself shouldn't set
you back more than $50 and mine draws under 30w with the drive asleep.
 
D

dterrors

kony said:
Didn't you ask about this already?

No, I didn't. I asked what mini-itx system to buy. I changed my
requirements to putting low-power as the number one factor, and small
is secondary. I said I'm willing to not get a mini-itx and instead get
a micro-atx- changes the spec quite a bit, right?
Again, it's not so useful to try to compare to a particular
Pentium II MHz speed because these are different
architectures. You can only use the Pentium II MHz as a
gauge if you are using a Pentium II or nearly identical
architecture. It is simply non-applicable when considering
the more specialized, highly- low-power-optimized CPUs that
are ultra low power.

I don't understand why that isn't an applicable comparison.
Instead you MUST factor for the specific demands placed on
the system. "network" tells us litte. "Server" a tiny bit
more... now we'd need to know what it's serving, and what
the server runs in the background, etc, etc.- ALL DETAILS of
what you're doing, not a random idea about what Pentium II
would do the job. I suspected you meant file server, and
this was already addressed last time so I have to wonder why
you didn't go ahead and build the system already?

Because I changed my criteria. I really don't understand why you need
"ALL DETAILS of what I'm doing". I want a low power x86 compatible PC
that's about as fast as a P2, can hold a ATA 3.5" drive, has some usb
ports, and 128 mb of ram, and fits either mini-itx or micro-atx.
That's what I want. That's a specific as I get.

A Pentium M is significantly faster than most other
alternatives, faster than a P-II 400, but also at full load
produces significantly more heat than the others too, so
determining the real need is very useful to target a thermal
load the system will bear, optimize for this fanless design
you mention above.

Maybe you need to know the ammount activity the processor will
typically be under? Sure, that's a fair question. (I don't know why
you need "ALL DETAILS", instead of just asking that.) It will be under
minimal load. For example, I like that guy's idea to look into "sleep
mode".
If you just want a random speculation without giving us more
details, you probably don't need a Pentium M for a
fileserver, but for a web server running scripts and a fair
load, you'd want one.

I actually suggested the pentium M because I was thinking that it might
consume less power than a PII. I know it's faster than a P2, but then
again, it was made 5 years later, and for laptops, so I thought maybe
it'd be less power eating. After all, the AMD Geode has a PR of 1500
and it doesn't even need a fan.
Ok, but only one? Servers often have some redundancy, like
a RAID1 if not RAID5 array.

Only one, as I specified.

Supposedly some WD drives have a slight edge but not enough
to worry about, go ahead and get the Seagate since that's
what you want. The power differences will be minor, again
not enough to worry about. For lowest power usage you'd
have to go to a laptop drive or flash memory (and suffer the
inherantly lower write cycle limit and low capacity).

Awesome info, thanks, I will definately get the seagate.
 
D

dterrors

This is excellent information, however, I'd rather run my own linux and
backup scripts, etc, on it. Hence the reason I say I want to build
one. But some of the ones on the list are DIY, that's good for me to
look into. I wish there was one pre-built like these NAS machines, but
that could let me install my own linuxes and apps. Either way, thanks,

dt
 
M

meow2222

Because I changed my criteria. I really don't understand why you need
"ALL DETAILS of what I'm doing". I want a low power x86 compatible PC
that's about as fast as a P2, can hold a ATA 3.5" drive, has some usb
ports, and 128 mb of ram, and fits either mini-itx or micro-atx.
That's what I want. That's a specific as I get.

Then buy a P2! How much simpler and cheaper does it get?

To cut back on power use, underclock it and unplug the cpu fan. Very
simple.


NT
 
D

dterrors

That may actually be good advice! The motherboard of the pc I want to
replace is an asus p2b-ds. I don't think the bios will allow me to
under clock it, though... I was hoping that there were some newer
procs that consumed less power for their processing capability...
 
K

kony

No, I didn't. I asked what mini-itx system to buy. I changed my
requirements to putting low-power as the number one factor, and small
is secondary. I said I'm willing to not get a mini-itx and instead get
a micro-atx- changes the spec quite a bit, right?

Ok.

It seems you are pretty much done.
 
K

kony

That may actually be good advice!

The advice as given might be possible, but was incomplete in
one crucial area- it may still run too hot to simply "unplug
the fan", and further, if the fan isn't running it should be
removed entirely, and further, a different type of heatsink
is usually used for best results in passive cooling (tall
widely spaced tines, instead of short rows of fins). Then
add a duct to direct air.
The motherboard of the pc I want to
replace is an asus p2b-ds.

Once again it would've been good if you had just provided
full information up front. It doesn't matter if you
understand why or not, that's so OTHER people can fully
asses the situation and make suggestions. Remember, nobody
is compelling you to do anything, but the only way to get
the high quality answers is to provide ALL information. So
far it is ridiculous how much time has been spent and we are
only now uncovering that you may well have a board that
would do as you need (except we still dont' actually know
what performance level you need for this mystery task).

I don't think the bios will allow me to
under clock it, though...

Did you check?
Most Asus boards will, except the OEM ones, though often
there are jumpers to do it, not bios settings... but
actually the jumpers are even better than bios settings for
this purpose.

There's more than one way to skin a cat though, you don't
actually need a board that supports underclocking to
underclock a P2 chip... but then once again, you have failed
to provide detail- what CPU was in that board. If it had a
100MHz FSB, it's trivial to cover up a pin or cut the
connecting trace to force it into 66MHz FSB mode, which of
course results in 2/3 of the original spec'd CPU clockspeed.

The thing is, clockspeed reduction is not as effective at
reducing heat as voltage reduction is. The idea underclock
scenario is one where the voltage is the thing you target
for reduction, and the clockspeed is the secondary concern,
it is lowered enough to get the target voltage stable. I'm
thinking of more modern platforms though, if you went with
that board with the multiplier locked pentium 2 processors,
you can't change that multiplier and the only clockspeed
reduction left is as mentioned above, dropping from 100 to
66 MHz FSB.

I was hoping that there were some newer
procs that consumed less power for their processing capability...

There are, the topic had shifted from a generic idea about
low heat towards the specifics of what you really needed...
at which point you decided to be counterproductive. It's
highly likely you have no idea what CPU performance level
you actually need and the more important factor is the
platform (mainly, motherboard) features. So it would be for
a general purpose fileserver, for example, that even a
Pentium 100 would suffice- but a pentium 100 compatible
motherboard lacks some other important features like large
HDD support, ACPI capable bios, ATX PSU support (in most
cases), possibly not supporting 128MB of memory, etc. It
may well be that the only thing that mattered was the
motherboard you chose, when instead you are only specifying
the CPU and refusing to come clean about what you need.

Low heat isn't a primary concern, there are many ways to get
there. Nobody here is going to be willing to spend the
weeks, months, even years to tell you about all the possible
ways to get an end result of low heat with all the myriad
parts that exist which are capable of low performance tasks.
Instead, given ALL the details, participants in the forum
can make the best suggestions. Without all the details,
it's just a random shot in the dark.
 
M

meow2222

That may actually be good advice! The motherboard of the pc I want to
replace is an asus p2b-ds. I don't think the bios will allow me to
under clock it, though... I was hoping that there were some newer
procs that consumed less power for their processing capability...

The faster the proc, the more MHz per watt. Probably your best optoin
is a P2 laptop.

Good thing about P2 desktops is theyre free in many countries. And they
dont need too much underclocking to run fanless. With an oversize sink
and a big card tube to the psu fan, and they can run at almost full
speed.


NT
 
D

dterrors

kony said:
Nobody here is going to be willing to spend the
weeks, months, even years to tell you about all the possible
ways to get an end result of low heat with all the myriad
parts that exist which are capable of low performance tasks.
Instead, given ALL the details, participants in the forum
can make the best suggestions. Without all the details,
it's just a random shot in the dark.

You know, you're the only one on either this thread or the previous one
that has made any kind of fuss about the amount information I provided.
You DO NOT need to know what I am using this box for. NO, you don't.
You DO NOT need to know that I am replacing a p2b-ds. Why not? Because
what I very clearly specified in my original post is that I want the
system to have either an itx or mini-atx mobo. The p2b-ds is full ATX.
My original question is not flawed for not mentioning that I'm
replacing a p2b-ds. I'd still rather have a smaller box, as I said in
my first post.

Further, you don't need to conclude that I need a Pentium 100. Why is
that a bad conclusion? Because I said it needs to be about as fast as a
P2 400, that's why. When I say "about as fast as a P2 400", what I
mean is "about as fast as a P2 400". I have a good understanding of
the difference between a p2 400 and a p100, hence the reason I
specified p2 400 and not p100. Maybe try looking at my information
rather than looking around it. Apparently, the more info I give you
the further you veer from the goal.

Here again is my requirements list, which was apparently enough for
everyone else:

http://groups.google.com/group/alt.comp.hardware.pc-homebuilt/msg/6d843876b52553a7
 
K

kony

You know, you're the only one on either this thread or the previous one
that has made any kind of fuss about the amount information I provided.


It could be because I'm either the only one that sees how
many options there really are, or that which option is best
depends on the variables you haven't specified, or it might
be a bit simplier to explain- maybe other people figure
there's no need to repeat same things somebody else wrote
already.

You DO NOT need to know what I am using this box for.

In a "I'm not going to use it" sense, you're right.
In a "suggest the best solution" sense, you're wrong.

NO, you don't.

Do you realize that you are the one with the problem?
You can't even build one system to a very simple
specification, while I can take damn near any system made in
the past 8 years and do what little you have described. So
the generic answer would be "randomly grab any system and
use it".

If you don't know how to randomly grab any system and make
it work, then we're going to have to extract more
information from you in order to suggest something you are
capable of doing, and with an end result that meets your
needs.

You DO NOT need to know that I am replacing a p2b-ds. Why not? Because
what I very clearly specified in my original post is that I want the
system to have either an itx or mini-atx mobo.

You're the one that seemed to think the idea of
underclocking was good when you mentioned that board- not I.

The p2b-ds is full ATX.
My original question is not flawed for not mentioning that I'm
replacing a p2b-ds. I'd still rather have a smaller box, as I said in
my first post.

Which would have been fine if you'd continued on with
further specifications but you got a mental block about the
rest of the details.


Further, you don't need to conclude that I need a Pentium 100.

I don't?
Until you specify the use, there's no reason to believe
otherwise, as you already demonstrated a complete lack of
understanding about why a generic CPU description is in
adequate to spec out a DIFFERENT platform for an unknown
use.


Why is
that a bad conclusion? Because I said it needs to be about as fast as a
P2 400, that's why.

.... and if you were PAYING ATTENTION, you'd have noticed
that I've told you several times that a different CPU
architecture will be significantly faster or slower at
specific tasks, that the only way to get "about as fast as a
P2 400" is to know WTF you're doing with the system.

When I say "about as fast as a P2 400", what I
mean is "about as fast as a P2 400".

If only you knew more than you do, you'd realize why you're
wrong. Citing some other CPU that is "on average" the same
performance as a p2 400, will on specific tasks be a quite
different performance level.

This is like CPUs 101, even the most basic knowledge about
CPUs would make this obvious. You're not capable of putting
this system together and you don't know what CPU you want,
yet you want to ARGUE with people who were trying to help
you.

That makes you an idiot.
 
L

Last Boy Scout

I think A-Open makes some Pentium M Micro-ATX Motherboards. They are like
PIII on Steroids and run at about 30 watts power consumption with a low
power CPU FAN. This Pentium M gear can be expensive. Mini-ITX can be a
little expensive as well.

I am still running an ASUS 1.2 gig PIII (Celeron) TUSL2-C and I like that.
It is the computer that keeps running. The Tulatin Core Celeron PIII
systems ran pretty cool and had a 256k L2 Cache. It is a shame they quit
making them so early. They were a good workhorse and run as well as a 1.8
gig P4(Almost). The Pentium M boards are just low-power PIII hybrids
designed to run like a P4.
 

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