[kde-linux] Re: KDE on high resolution monitor

Duncan 1i5t5.duncan at cox.net
Wed Dec 8 10:31:32 UTC 2010

yahoo-pier_andreit posted on Wed, 08 Dec 2010 09:04:55 +0100 as excerpted:

> I have a dell latitude with intel i7 nvidia NVS 3100M and screen
> 1920x1080 resolution, using KDE 4.4 stable suse, well with high
> resolution monitor I found some problem usng kde:

Hi.  I'm running kde4 (4.5.4)[1] with dual 22-inch (570mm) LED-lit 
1920x1080 LCDs, stacked for 1920x2160 resolution total, here, so yeah, 
similarly high-res.

> 1- I can change the font dimension by system settings but if I bigger
> the font the dimension of Kmeunu doesn't change so the result is big
> font in small container, ugly and difficult to use
> 2- I can change the font dimensions in KDM splashscreen but the window
> where username and password is shown doesn't change, result is big
> unreadeable font in a small case
> 3- I cannot change the tabs and theyr font dimensions in chromium and
> firefox, result very small tabs
> 4- Icons in system tray and Kmenu and other icons remains always small
> even if I bigger the panel
> any suggestion on this issues :-)

Working backward, as it's most convenient...

4.  Icons.  These are a standard size, at least partially set in kcontrol
[2].  Unfortunately, the original kde4 kcm layout was confusing, and they 
changed the organization a bit for kde 4.5, so I can't tell you exactly 
where to look in 4.4, but in 4.5, the icon settings are in the icons kcm, 
found under common appearance and behavior, application appearance.  On 
the advanced tab, you can set the size of various icon categories.  
However, you'll have to play with them a bit to see which category works 
for what as I've not experimented to that extent.  Also note that the 
standard icon size is 32x32 px, and setting a different size, for non-kde-
native apps, may result in rather less clear icons.  For that reason among 
others, it's possible the systray icons in particular, are hard-coded to 

Generally, you may find the zoom effect helpful in this regard.  It can be 
enabled under desktop effects, center tab (all effects), tho AFAIK it does 
require OpenGL.  I customized my keyboard shortcut triggers in the same 
place (there's zoom-in, zoom-out, and normal-size shortcuts).  You can 
choose between the full-screen zoom and pan, the magnifier, and the 
looking-glass/fish-eye, each of which use the same keyboard triggers so 
effectively only one at a time activates.  (Also, looking-glass/fish-eye 
requires a more advanced OpenGL which might not be available on all 
graphics hardware/drivers or may be buggy or slow, compared to the others.)

You might also find the sharpen effect useful, tho the effect isn't 
exactly natural looking and some may find it annoying.  Again, this effect 
may not work on less advanced OpenGL graphics hardware/drivers.

3.  Firefox/Chromium tab fonts.  I don't have chromium installed so have 
no idea how it works, but firefox is a gtk app.  There's an option in 
kcontrol colors to apply kde's scheme to non-kde apps (including gtk), but 
depending on how they are started, they may or may not inherit the correct 
environment to actually pickup the kde settings.  Starting them from the 
menu and IIRC from krunner picks up the settings, but from konsole, won't, 
IIRC.  What I finally did here was setup a firefox launcher script with 
the appropriate environment to pick it up, and put that launcher first in 
my path, so when I said launch firefox, it found that script (and 
therefore picked up the kde settings) before it found the system firefox 
binary.  But of course that's a bit advanced for those who aren't 
comfortable at the command prompt and with shell scripting.

Another alternative, if you have gnome installed as well, is to run the 
gnome config thing and set fonts, etc, there... or figure out how to 
modify the settings directly, from google or the like.

Of course, the kde browser is konqueror, and it obeys kde settings since 
it's a kde app, but it doesn't have the wide variety of extensions that 
firefox does, and many people find it problematic for that or other 
reasons.  FWIW, konqueror is my default browser, but I have firefox 
installed as well and use it when I need to enable scripting (noscript is 
SO much easier to work with than konqueror's scripting, as at least with 
noscript, you can figure out which sites are /trying/ to run scripts and 
decide what you want to enable and what not, something that's essentially 
impossible with konqueor without reading the actual page code) or where 
konqueror has issues.  I also run privoxy, formerly junk-busters, as my 
junk busting proxy, for both konqueror and firefox.

2. KDM.  I don't use a *dm, preferring instead a text login and then 
startx, set to start kde.  As such, all I can say here is check the next 
one, as it's likely to help.

1. General kde font dimensions.  You mention changing these, but there's 
actually two ways to change them, and you don't mention which you are 

You can of course change the individual font sizes, OR, you can change the 
DPI (dots/pixels per inch), using the force fonts DPI setting.  Since font 
sizes are measured in points, 72 points to the inch (thus, 72 DPI, 1 
pt=1/72 inch), changing the computer's (really xorg's) idea of the DPI 
changes how big a font configured to say size 8, really is.  If you tell 
xorg that your DPI is really high, it'll use more pixels to draw a font at 
the same font size (points), compared to if you tell it that your DPI is 
really low.  Since the real pixels on screen remain the same size as long 
as you continue using the same resolution, forcing the DPI artificially 
high (higher than it actually is) makes fonts appear bigger at the same 
point size, since xorg uses more pixels to draw them because it believes 
it has to to make them the proper size -- you've faked it out!

Meanwhile, a bit of xorg dpi background is in order.  Years ago, if you 
changed xorg (then xfree86) version, you'd very likely have to adjust your 
fonts if you hadn't set a specific DPI yourself, as they changed the 
default DPI several times over the years.  These days, xorg reads the ddc/
edid from the monitor itself, getting the native/preferred resolution as 
well as the size of the monitor, and does the math internally to come up 
with a correct DPI, so most of the time, it gets a correct DPI setting and 
it's no longer necessary to set it manually, as long as you're satisfied 
with the "normal" result.

That said, it's still possible to set this manually and many people choose 
to do so, either because they don't like the normal/correct settings, or 
because they have software that assumes the old default DPI (IIRC, 96 was 
the MS Windows default for years, and I'd guess 120 might have been the 
Apple Mac default).

Now, there's different ways to set this.  As mentioned above you can set 
it via KDE GUI, but that's not going to be in effect when you run Gnome or 
something else, and probably won't take effect until you login to kde, so 
won't be in effect at the kdm graphical login, either.  Also, kde only has 
the three settings, disabled (xorg sets it), or forced 96 or 120 DPI.

The alternative way to set it is in your xorg settings, xorg.conf, or for 
newer xorg-server (1.8+, IIRC), a file in xorg.conf.d.  The setting used 
for this is the DisplaySize setting in the appropriate Monitor section.  
See the xorg.conf manpage.  For quite some time I had to set this manually 
here, not because I wanted to change the natural setting, but because xorg 
screwed up the calculation when multiple monitors were in use, and before 
that, because it didn't detect them well or at all so it'd fall back to 
defaults if the monitor size wasn't set, and the defaults had a way of 
changing between versions!  Those bugs are now fixed and I no longer have 
that setting, but I still know how and where to set it, should I need to.

Depending on how comfortable you are reading manpages and directly editing 
your xorg configuration, that pointer may be all you need.  However, if 
you decide you want to set this in xorg but aren't familiar with editing 
it or with reading manpage documentation, you might need more help.  Ask 
if you want it, but I'll skip it for now in case you decide to use other 
alternatives (like the kde dpi setting) or already know about editing your 
xorg config.  If you do want further help, please post the version of xorg 
you're running, and see if there's an xorg.conf file or xorg.conf.d 
directory in /etc/ or /etc/X11, and post the contents, if so.  FWIW, you 
can see what X is using for DPI now by reading the Xorg.0.log, probably 
located in /var/log.  Posting that may be helpful as well.

[1] 4.5.4 now, I've found staying up with the latest is good, as they're 
still fixing bugs at a rapid rate, and honestly, 4.5.x is the first 
release I'd consider release quality in any case, tho 4.4 was close, rc 
quality -- do know that the new releases work best with an entire system 
similarly updated, tho, I'm running mesa 7.9, xorg-server (1.9.3-
rc2), a live-git-sources kernel from after 2.6.37-rc5, etc.

[2] kcontrol, wrongly aka system settings:  In kde3 it was called kcontrol, 
quite accurate as at least as shipped by kde, almost everything configured 
there (with exceptions such as system time) is user-specific kde settings, 
*NOT* system-wide settings applying to all users and both inside and 
outside of kde.  Thus, the kde4 name is a serious regression that hardly 
describes the settings there at all.  Unfortunately, unlike kcontrol, 
"system settings" is also FAR too generic to be properly googlable, as 
well, making searching for it now essentially impossible.  FWIW, the 
individual modules are still called KCMs, kcontrol modules, just as they 
were in kde3, and IMO, the user displayed name should revert as well.  I 
continue to use the properly descriptive and googlable name, but 
constantly find myself explaining, as here, so newbies never exposed to 
kde3 know what I'm talking about.

Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman

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