[173167] in North American Network Operators' Group
Re: Net Neutrality...
daemon@ATHENA.MIT.EDU (Owen DeLong)
Fri Jul 18 18:54:10 2014
X-Original-To: nanog@nanog.org
From: Owen DeLong <owen@delong.com>
In-Reply-To: <CAP-guGXMBcxTyqStvDUuKzwid=0PoM1GQzXS3ydOYSom-t48LA@mail.gmail.com>
Date: Fri, 18 Jul 2014 15:48:48 -0700
To: William Herrin <bill@herrin.us>
Cc: Rob Seastrom <rs@seastrom.com>, "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
On Jul 18, 2014, at 11:35 , William Herrin <bill@herrin.us> wrote:
> On Fri, Jul 18, 2014 at 2:05 PM, Rob Seastrom <rs@seastrom.com> wrote:
>> Michael Thomas <mike@mtcc.com> writes:
>>> On 7/17/14, 2:15 PM, Valdis.Kletnieks@vt.edu wrote:
>>>> /me makes popcorn and waits for 4K displays to drop under US$1K and
>>>> watch the network providers completely lose their shit....
>>>=20
>>> =
http://www.amazon.com/Seiki-SE39UY04-39-Inch-Ultra-120Hz/dp/B00DOPGO2G
>>>=20
>>> $339!
>>>=20
>>> I use it for doing dev. It's *fabulous*.
>>=20
>> "Refresh rate is limited to 30Hz with 4K"
>>=20
>> Bracing for my first seizure ever in 3... 2... 1...
>=20
> Hi Rob,
>=20
> An LED screen doesn't refresh the way a CRT does, right? The light
> doesn't flash and fade, it stays constant until the next change. So
> why would a 30 hz refresh rate make any difference at all for tasks
> which update the screen less often than 30 times a second? Mike did
> say he used it for doing software development.
Well... Yes and no.
An LED screen doesn't refresh the way a CRT does, that part is true.
However, the brightness of any particular color of any particular pixel =
in any LED
screen is usually controlled by a process known as Pulse Width =
Modulation (PWM)
where the LED actually turns on and off several thousand times per =
second and
modifications of the ratio between the on-time and off-time in those =
cycles are
used to control the apparent brightness. As such, the LEDs are actually =
turning on
and off (flickering) much much faster than any CRT would, but it's not =
the same
kind of flicker.
However, most "LED Screens" aren't actually LED screens, most of them =
are
LED backlit CRT Screens. (I didn't look at the specs on this one in =
detail, so
I don't actually know which type it is).
This gets further complicated by technologies such as selective dimming, =
etc.
Owen
