[Beowulf] LCD monitors, please...
Robert G. Brown
rgb at phy.duke.edu
Mon Dec 20 07:17:45 PST 2004
On Sun, 19 Dec 2004, Jim Lux wrote:
> 1) Design life is MUCH shorter on the monitors than the TVs. Typically the
> design is for half brightness after some 8-10k hrs of use.
> 2) The spot size on a TV is bigger than on a computer monitor (it makes it
> brighter, but has less resolution, no big deal on a TV that reproduces, at
> best, about 500x500 pixels). (For the technically inclined, it has to to
> with the accelerating voltage, the beam current, and focus electrodes in the
> electron gun)
> There's also the issue of seams.
> If you look for projectors (the NCSA approach), they're still quite pricey,
> at least for decent ones.
I'm getting LCD monitors exclusively at this point. This is for several
a) They use perhaps 1/3 the power. This defrays perhaps $100 of their
cost over a 3 year plus projected lifetime.
b) They are coming way down in cost. I just (yesterday) bought a 17",
1280x1024 LCD display for my house for $270 -- even adding a 3 year
service contract for $50 it was only $320 plus tax. After Christmas I
imagine they will drop another 20%. Kick in the $100 in power savings
and they are pretty close to break even with CRTs in amortized cost
c) CRTs are dangerous and environmentally unsound. Dangerous because
they produce wavelengths that can be damaging to skin and eyes under
chronic long-term exposure conditions. Environmentally unsound because
the screens are full of lead to protect you against the radiation and
because they waste a lot of energy. Duke currently charges folks $10
per monitor to safely recycle the monitors and keep them out of
landfills, where they will >>eventually<< contaminate the ground water
with lead and arsenic. My eyes have really deteriorated over the last
two years -- some of it is doubtless plain old age-related presbyopia,
but some fraction of it may well be due to close to 30 years worth of
hours every day spent in front of an electron gun shooting ionizing
radiation straight at my eyes. Radiation absorption is a quantum
process; so is radiation damage. So a leaded screen reduces the
probability that a soft X-ray gets through but doesn't reduce the damage
done by the ones that GET through.
d) They are a hell of a lot more convenient in all other ways than
CRTs -- smaller footprint, lighter, portable, less supporting
electronics. Building a wall of screens, you can actually hang them ON
a wall without any special shelving or being likely to tear down the
wall by their sheer weight. You can probably unmount them from their
frames altogether and assemble arrays of them with very narrow seams
(perhaps <1 cm total seam).
e) CRT-based TV's and monitors both are obsolete technology. I
predict that in three years they simply disappear. A number of
companies are now mass-producing the LCD screens and are just enjoying
the end of the period of relatively high margin sales as competition and
increased production capacity drives prices down. I expect 17" monitors
and flatpanel TVs to cost in the lower/upper $200's by this time next
year, and at that cost who will buy CRTs?
Robert G. Brown http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567 Fax: 919-660-2525 email:rgb at phy.duke.edu
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