High resolutions possible?

My first post here. I am new to open-source and small devices like
beagleboards. I have two beagleboards Rev-C3 and C2 and Dell E198WFP
(1440*900 19") and E228WFP (1680*1050 22") LCD monitors. I want to
use them with my beagleboards at native resolutions. I am not going
run video at these resolutions. I only want the GUI desktop running at
that resolution. I don't care if the frame-rate is low. I want to know
if this can be done.
I am guessing that refresh-rates might need to be lowered for this to
be possible. I want to know if low refresh-rates can damage my panel.
Also I need help running beagleboard at other custom resolutions. How
do I go about using custom resolutions?
What is pixel clock?

Please help me with above 3 queries.

All LCD/VGA monitors obey the VESA published standard regarding video
timings/refresh rates/etc.
You can refer to the CVT (Coordinated Vesa Timings) or the GTF
(Generalized Timing Formula) timing calculator spreadsheets to figure
out the pixel clock required for a certain VESA resolution. GTF is
more suited for older analog monitors, while the newer LCD panels
typically stand by the CVT timings (options for reduced blanking,
etc.)

The one limitation you have to be aware of on the OMAP3 is the maximum
pixel clock it can generate, which is 75Mhz. The option to lower
refresh rates will not work here since most monitors have a set of
refresh rates they work with (typically 60Hz, 70hz, 75Hz, 80Hz). Going
out of these rates will prevent the monitor for starting.

Generalized pixel clock formula = (horizonal_active +
horizontal_blanking) * (vertical_active + vertical_blanking) *
refresh_rate
horizontal_blanking = horz_front_porch + horz_back_porch
vertical_blanking = ver_front_porch + ver_back_porch

Can you tell me where I can find these specifications for my monitors.
The Dell website gives very simple specs like refresh rates, panel
type and resolutions, etc. Is there a utility like gpu-z or cpu-z
which can probe and tell? I have windows 7 enterprise and Ubuntu 9.04.

I found out the spec by using "add custom resolution" option in nvidia
control panel and comparing it with pixel clocks for the resolutions
mentioned in the user guide.
I don't know how to safely change these settings.
I can achieve 72Mhz pixel clock with 32Hz refresh rate at 1680*1050
res. I tested that resolution but monitor just went blanked, and it
can back only after pressing Esc multiple times which closed all
nvidia windows.
Is there some way to run it at this resolutions?

I have LG W2442PA monitor and the highest resolution which it is capable to
show with beagleboard is 1680x945 @49Hz, and it is using 86.5MHz pixel clock.
Trying any higher resolutions at lower refresh rate makes my monitor just show
a banner with the information about the attempted video mode and a notice that
it is out of range. My guess is that monitor should be intelligent enough not
to permit any mode that can physically damage it.

I also successfully tried beagleboard with some 17-inch ViewSonic at native
1280x1024 resolution before, but don't use this monitor anymore.

I think that 1440x900 will probably work fine, but 1680x1050 is unlikely.

Anyway, everything needs to be verified first. Some kind of compatibility
table and the list of recommended monitors which are known to support
native resolution with beagleboard would be nice.

Siarhei Siamashka wrote:

My first post here. I am new to open-source and small devices like
beagleboards. I have two beagleboards Rev-C3 and C2 and Dell E198WFP
(1440*900 19") and E228WFP (1680*1050 22") LCD monitors. I want to
use them with my beagleboards at native resolutions. I am not going
run video at these resolutions. I only want the GUI desktop running at
that resolution. I don't care if the frame-rate is low. I want to know
if this can be done.
I am guessing that refresh-rates might need to be lowered for this to
be possible. I want to know if low refresh-rates can damage my panel.
Also I need help running beagleboard at other custom resolutions. How
do I go about using custom resolutions?
What is pixel clock?

Please help me with above 3 queries.

I have LG W2442PA monitor and the highest resolution which it is capable to
show with beagleboard is 1680x945 @49Hz, and it is using 86.5MHz pixel clock.
Trying any higher resolutions at lower refresh rate makes my monitor just show
a banner with the information about the attempted video mode and a notice that
it is out of range. My guess is that monitor should be intelligent enough not
to permit any mode that can physically damage it.

I'd say that the days of monitors getting physically damaged by wrong video signals
are over since LCDs using DVI/HDMI....

I think that 1440x900 will probably work fine, but 1680x1050 is unlikely.

1440x900 works fine. Never tried higher than that.

-Deven

I will try 1440x900 on e198wfp after the holidays.
Thanks for help everyone.