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a60fb26
(Get the code!)
Fabio Massimo Di Nitto at 2006-04-27 17:13:34 EEST wrote:
> There is no way to decide what is best for user A or B.
> This request conflicts with what tons of other users asked the other way around.
It's not true - there is a simple way to check if CRT monitor supports 75 or 85 Hz mode at recommended resolution, so, there is no reason to select higher mode with 60 Hz refresh.
according to TCO99 standard vertical refresh frequency *must* be >=85Hz (look at Section 2 (Visual ergonomic
- Image stability) of TCO99:
http://
There is simple table of mandatory resolutions and vertical refresh for CRT monitors:
CRT Size VRefresh Resolution
14"-15" >=85 Hz >=800x600
17" >=85 Hz >=1024x768
19"-21" >=85 Hz >=1280x1024
>21" >=85 Hz >=1280x1024
Btw, TCO99 recommended vertical refresh is 100Hz and I think it would be very nice to select according display mode if possible (if monitor could work with mandatory resolution at 100Hz)
Monitors vertical refresh depends on maximal horizontal sync, I can provide simple table for recommended modes:
800x600 @ 85Hz hsync: 53 kHz (low quality 15" monitors and good 14" have maximum hsync ~54 kHz)
1024x768 @ 85Hz hsync: 68 kHz (good 15" and low quality 17" monitors have maximum hsync ~70 kHz)
1152x864 @ 85Hz hsync: 77 kHz (most 17" monitors and low quality 19" have maximum hsync ~85 kHz)
1152x864 @ 100Hz hsync: 89 kHz (high-end 17" monitors and most 19" have maximum hsync ~95kHz)
1280x1024 @ 85Hz hsync: 91 kHz (most 19" and low quality 21" have maximum hsync ~95kHz)
1280x1024 @ 100Hz hsync: 107 kHz (high-end 19" and most 21" have maximum hsync ~110kHz)
1600x1200 @ 85Hz hsync: 106 kHz (most 21" have maximum hsync ~110kHz)
For example my old 17" Hansol 701P monitor is made at 1998 and supports only TCO95, it has maximal horizontal sync 85kHz and I usually use 1024x768 @ 100Hz and sometimes 1152x864 @ 85Hz
As you see, it's always safe to choose resolution with 85 Hz vertical refresh for all monitors, which has maximal hsync >=68 kHz, only low quality 15" monitors can't work with 1042x768 @ 85Hz and low quality 14" monitors can't do 800x600 @ 85Hz, so we can discuss which mode would be better for monitors, which horiz sync is less 68 kHz
If there are posibility to know real monitors CRT size, then we can set resolution with 100 Hz vertical refresh on 17" monitors with maximal hsync >= 89 kHz and 19" monitors with maximal hsync >= 107 kHz
There are lots of hardware and eyes safety sites, which recommend to use 800x600 on 14"-15", 1024x768 on 17" and don't recommend to use vertical refresh lower than 85 Hz, look for example at http://
According TCO99 and TCO2003 85Hz is *mandatory* and 100Hz is recommended, so Ubuntu Linux developers should care about users eyes.
A quick search reveals that this is usually recommended by most:
http://
"Most people use CRT (Cathode Ray Tubes) screens like TV screens. These screens have a single electron ray that has to light up dot after dot, line after line.
It does this at a certain speed. With TV it is 50 Hz (50 screen scans per second) and with PC's it's 50 to 60 Hz by default. This 'refreshing' of the screen is why TV and computer screens flicker. This flicker can cause tremendous eye strain and headaches in some people."
http://
"You might find out that your refresh rate is set to 70 Hertz or even lower. If so, check out if there are higher refresh rates in the drop down menu. Consider 75 Hz or higher. After having increased the refresh rate you may be pleasantly surprised to find out that the monitor is now easier on your eyes!"
I don't understand the resistance shown by Ubuntu developers to offering the medically best resolution to non-technical users by default...
Btw, I'm developer of Ubuntu-based distribution - Baltix GNU/Linux and I will improve default resolution choosing for CRT monitors method in Baltix distro if Ubuntu developers don't care about users health.