In article <92a58$50c3ca65$5419b3e4$
84...@cache1.tilbu1.nb.home.nl>,
Skybuck Flying <Window...@DreamPC2006.com> wrote:
>I play to buy a new computer by 2016, currently I am concerned that the
>computer I want is not for sale/possible.
>
>So far intel and/or amd is not selling passively cooleable CPUs for desktops
>?! Could this explain the decrease in PC sales ? People diverting to
>noiseless tablets ? *
>
>Amazing that no passively cooleable cpus seem to be for sale ?
>
>With passively cooleable cpu I consider:
>
>1. CPU + heatsink with fins smallist, no fan, no other things, except maybe
>thermal paste interface material between cpu and heatsink.
>
>So two questions:
>
>1. Which desktop cpu by 2016 will be passively cooleable ?
>
>2. How many watts are passively cooleable with a small heatsink/fins, like
>gt 520 from asus is a good example.
>(Also the motherboard must be passively cooled as well as all other
>components except perhaps power supply, though if a modest power supply is
>needed might be passively cooled too, but a little bit of airflow seems
>wise... though would be cool if it wasnt needed at all, than no dust in pc
>which would be excellent.)
As is so often the case, your questions are so poorly defined that
there is either no answer to them, or dozens of answers (some being
quite silly). For example, you can certainly cool a thousand-watt
device with a simple passive heatsink with fins, but you're likely to
find the operating temperature and lifetime of the device to be
inadequate for home use :-)
There are now, and have been for years, Intel (and compatible) CPUs
which gave good performance for their era, and which were passively
cooled. Many of these were and are quite suitable for use in desktop
systems and notebook computers, assuming proper system design.
A lot of these are sold as "industrial computer" or "embedded
computer" devices rather than "desktop", but they run the same code
and do the same jobs... the terminology is as much marketing-speak as
it is real.
For a simple example: I've got a single-core, hyperthreaded Intel 1.6
GHz Atom N270 at the heart of my home firewall / VoIP server / email
server / Web server, on a mini-ITX motherboard mounted in a
desktop-computer tower case. It's passively cooled... just a small
finned heatsink... no fan on the CPU or on the motherboard chipset or
DRAM. The only fan in the box is in the ATX-style power supply... and
I could have done without that if I had bought the version of this
motherboard which has a simple 12-volt power input jack, and ran the
whole system from an external switching "wall wart" power supply.
A lot of the "industrial PC" systems I've seen are not only passively
cooled, they are sealed boxes (hermetically sealed or close to it)...
intended for operation under harsh conditions (dust, humidity,
vibration) they depend entirely on passive cooling. Typically they'll
have some sort of mechanical head-spreader between the CPU and the
case, so the case and its external fins serve as the cooling system.
If you're fixated on "desktop" CPUs (i.e. those which can be installed
into sockets on traditional motherboards in traditional "desktop"
cases)... well, the vendors seem to focus more on performance than on
passive cooling, and so you may not find anything to your liking.
That's even more true for GPUs, for which performance is almost
everything... and so they run the chips fast, and this generates a lot
of heat. I rather doubt that these traditional-market "desktop"
systems will focus on passive CPU cooling any time soon - there's not
much incentive for the manufacturers to do so.
You can reduce the heat generated in almost any CPU or GPU by
underclocking it and turning the voltage down, but of course this
costs you much of the performance.
As to your question about "how many watts" - until you define the
actual heatsink, *and* the environment in which it's operating (e.g.
case air-flow if any, extra heat spreading, air temperature inside the
case, etc.), tell us what sort of temperatures the CPU chip can
handle, and how long you want the CPU to survive the heat, there's no
way for anybody to give you a solid answer.
As a very rough rule of thumb, though, I would suggest that running
more than about 4-5 watts, in the chip the size of a modern CPU, will
require either some form of forced air across a heatsink, or some
fairly direct thermal connection of the chip to a larger heat
spreader. Beyond this point, a modest finned heatsink which depends
on air convection and radiation isn't going to keep the chip cool
enough for a good long lifetime. The larger the heatsink you are
willing to tolerate, the more heat you can dissipate without needing
forced airflow.
This all may be irrelevant, though. Apparently, Intel has announced
that they plan to discontinue their lines of desktop CPUs which plug
into sockets. They're going to be moving their new CPU lines to
BGA (ball-grid array) only, and these must be soldered to the
motherboard. "Enthusiasts" will no longer be able to buy a
motherboard with socket, and populate it with the CPU of their
choice... you'll have to buy the motherboard with the CPU already
soldered on, and will not be able to change it (BGA removal and rework
is possible but it's a terror, from all I've heard).
So, your 2016 Dream PC may be an Impossible Dream.
--
Dave Platt <
dpl...@radagast.org> AE6EO
Friends of Jade Warrior home page:
http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!