ToolPackinMama said:
I have a friend who only needs something for email and web-browsing.
She's not what you'd call a power-user. I am not even sure why she
wants a desktop unit, when she has a tablet. Maybe for the bigger
monitor screen.
Buy an Intel NUC. Less work.
Processor is soldered in place. 15W processor. A bit gutless
if doing Photoshop. 2 Core 4 Thread. 1.3GHz when doing multithreaded
things like Photoshop or 7ZIP compression (7Z format). Turbo to 2.6GHz.
Meaning when surfing, single threaded, the processor runs faster as
long as there isn't too much background loading. Benefits might
include less noise than other solutions.
http://www.newegg.com/Product/Product.aspx?Item=N82E16856102069
http://ark.intel.com/products/75028/Intel-Core-i5-4250U-Processor-3M-Cache-up-to-2_60-GHz?q=i5-4250U
*******
MiniITX has processor boards available with sockets. You can
install a more powerful processor (fan cooling, a bit more noise).
MiniITX tend to be powered by wall adapters with Pico power supplies
for inside the box. Builders like to build compact boxes, but then
you must pay careful attention to the dimensions of everything,
like using slim laptop optical drives, laptop hard drives or SSDs,
special low-profile DIMMs, and so on. Boxes typically include
a single PCI Express slot, but depending on your power limitations,
you can't put a low-profile gamer video card in there. The thermals
would be too hard to get right.
This combination site plus store, offers examples of mini-ITX.
http://www.mini-itx.com/
http://www.mini-itx.com/store/
You can see on their feature page right now, an enclosure
designed to dissipate heat.
http://static.mini-itx.com/store/images/m5xp-montage.jpg
But the smaller those cases get, the harder the installer
has to work. Lots and lots of dimensions to check. Does
my cooling fan fit ? Will this 150W wall adapter be enough ?
And so on.
(Page containing AC wall adapter, Pico DC Converters to match...)
http://www.mini-itx.com/store/?c=10#picoPSU-150-XT
(Specs for the Pico, usually found elsewhere...)
http://resources.mini-box.com/online/PWR-PICOPSU-150-XT/PWR-PICOPSU-150-XT-manual.pdf
12V @ 8A (Motherboard CPU power, CD/DVD if desktop drive)
5V @ 6A (Used by hard drive, CD/DVD drive, motherboard)
5VSB @ 1.5A (USB bus)
3.3V @ 6A (Motherboard rail)
-12V @ 0.05A (Serial port RS232 if present)
Total = 150W of DC power
Input - 12V regulated (presumably passed straight to the motherboard)
Not for usage with car battery (not a "wide-range" input).
On this page, I can see some "recommendations" printed next
to the motherboards. Like 65W CPU plus LGA1150 (upgradeable)
motherboard, to be combined with 150W wall adapter and
150W Pico converter (for inside the box). The wall adapter
makes a higher voltage, like just to make up some numbers
maybe it makes 15V @ 10A. The Pico converter is a small board
that plugs into the main ATX power connector, and it is mechanically
mounted there. Unlike an ATX power supply, the Pico can be just
a "buck converter" design, and needs to be 90% efficient so it
will not overheat. The wall adapter provides isolation (has a
transformer between primary and secondary side of switcher), so
the wall adapter provides the same level of isolation as the
ATX supply does. The Pico board then converts the 15V to 12V,5V,3.3V
or whatever else is required. Each "rail" on the Pico has a current
limit that must be followed.
To be a petite system builder, I recommend the purchase of
a clamp-on *DC* ammeter. You can buy an ATX extension cable
(male and female connectors, 24 wires joining them), and
you slip your clamp-on ammeter around the wires. You
build up your mini-ITX on the bench. Use a Linux LiveCD,
get a copy of Prime95 (mersenne.org/freesoft) and do a
torture test. Now, using the clamp-on ammeter, you verify
the current flow levels coming out of the Pico.
Wall_adapter -------- Barrel_connector ----- Pico ======== Mini-ITX DUT
24 pin
cable and loose
wires
The reason for doing this, is "characterization". Did I do
my power calcs right ? Is the Pico close to overload ? How
much air has to move through the Mini-ITX case to keep
the casing cool ? These are things you are preparing for,
by measuring the current.
I haven't built any of these things, and I only recommend
this tech to "well motivated" individuals. Do you really
want to get into this business ? You will end up with
a few leftover parts, as some experimentation will
be inevitable as you "build and learn". Like those
DIMMs you bought, which were too tall to fit under the
CPU cooler. And so on. Really no different than the
graveyard materials from ATX builds. A lot of the
same principles apply. Really, you should have acquired
all the skills to build a small box, from building a
large box. If you build a gamer box for someone,
you had to work out max_power for the internal components
and select and position enough fans to keep the case cool.
The smaller builds, it's like a "ship in a bottle". Everything
you do is a mechanical disaster waiting to happen.
Paul