How to determine max supportable display resolution?

Question

I'm trying to determine what is the highest monitor resolution that will be supported by a computer.

System

• Win XP-era Compaq Presario SR1750NX that contains

• Radeon Xpress 200 integrated graphics on an AMD Athlon 64 based motherboard.

  The Radeon Xpress 200 uses shared video memory (UMA). The computer has 3 GB RAM. (I'm not familiar with how UMA works and whether the video can access as much memory as it needs, or how much that would be.)

• It is currently running Linux Mint 17.0. I understand that AMD has a Linux version of Catalyst. However, the Xpress 200 probably pre-dates ATI's acquisition by AMD, and the appearance of the UI looks generic, so the driver is probably FOSS, and possibly required some reverse-engineering.

• The only built-in video connector is VGA. A VGA connector has no limit on resolution, but I understand the output quality at higher resolutions depends on the DAC and other factors.

Xpress 200 Info

The only thing I've seen that deals with maximum supported VGA resolution of the video chipset, itself, is the link posted by Daniel B in a comment, below. The "for Intel architecture" version of the Xpress 200 is spec'ed to support up to 2048x1536 (apparently a common spec based on a 400MHz DAC). Assuming the specs are the same in the "for AMD architecture" version, that would appear to be an upper limit. It isn't clear whether other factors would limit it below that (e.g., maximum memory it can use).

Usage

I don't think this affects anything, but just in case, the intended use is a lot of screen real estate for static content (large spreadsheets, lots of browser tabs, and the like), I'm not trying to view hi-res video or do 3D rendering.

Info From The System

Some years ago, I upgraded the monitor to 1600x900, just guessing that it would be supported. The available resolution settings under monitor preferences lists 1400x1050 as the only higher resolution, which is virtually the same total pixel count as the current monitor. However, I don't know if this reflects system assumptions based on the current monitor or the actual system limitation (or perhaps the limit of the Linux driver). The Linux driver does not have an explicit "list all" option.

Update

• I checked with AMD and HP to see if they had any useful specs. Answer: No.

• I used the xrandr command to see what it might show, which produced this (followed by available settings for the current monitor):

  Screen 0: minimum 320 x 200, current 1600 x 900, maximum 4096 x 4096
VGA-0 connected 1600x900+0+0 (yada yada...)

  The 4096 x 4096 maximum refers to the virtual screen size (maximum framebuffer), rather than a (useful) resolution possible from the VGA port. Would that imply at least that the chipset limit is not further limited by memory (one variable eliminated)?

What I'm Looking For In An Answer

I'd like to get a higher resolution monitor, but don't know how to determine what the limit supported by the system would be, or what factor is the limitation.

• An answer for this particular computer would be great. If that can't be answered without available specs, somebody actually using a higher resolution monitor on a similar system would be good evidence.
• In a more general sense, how do I go about determining the limit for a given system? Is it just the chipset limit (in which case, I probably have an answer, already), or can that be further limited by other factors (memory, drivers, etc.)? If there can be further limits, can those be determined in a practical way, or does it basically come down to just locating specs?

Answer 1

The monitor sends out EDID data which contains the monitors ability list.

See here for more details.

https://unix.stackexchange.com/questions/114359/how-to-get-edid-for-a-single-monitor

How do you find out a laptop screen panel manufacturer / model with Linux? (Samsung, LG, Chi Mei, etc)

ls /sys/class/drm/
cat   /sys/class/drm/card0-DP-2/edid

Answer 2

Back in the old days of CRT screens (the big ones with the holes on top), the display resolution was solely determined by the maximum resolution supported by your graphics card (CGA,EGA,VGA,SVGA,....) and of course your level of presbyopia (or how small a letter you can read). This was an attribute of CRT monitors due to their analog nature.

Nowadays, though, and since the advent of "fixed pixel number screens" (or digital screens) like LCDs, TFTs, ... the issue with the resolution has been quite simpler!

Now, there is The Display resolution which is one and only one for each display panel. This very specific resolution is the only one that would not blur your monitor colors or otherwise distort what you see due to up-scaling/down-scaling to make the selected resolution you set in your operating system fit into The Display Resolution. This is simply because it corresponds to the actual number of pixel elements your digital display contains.

More about screen resolutions can be seen in :
https://en.wikipedia.org/wiki/Display_resolution

To sum up, there is still a "maximum resolution" that is what your graphics card supports, and it will work even though distorted, but you would not want to leave the native resolution of your LCD or TFT monitor because you will have less than optimal image quality.

The only way your could break yourself out of these boundaries is if you plugged your laptop to an external monitor supporting a different native display resolution (say for example HP S2331 which supports 1920x1080). I have been searching around and couldn't find what the native resolution of your laptop's panel is (probably if you look below and hit in google a serial number and try to find the actual part number of the panel itself you will stand a better chance, but there is also the easy way! Just change resolutions starting from the standard for your monitor's inches and stop when the blur goes away...! You could even plug your old laptop to a Full HD screen and if your graphics card and your processor can reproduce HD material get a Full HD 1080p resolution. (I doubt that though... but theoretically it is possible).

Based on the discussion below, I realized that you are after a standardized test for a full system performance over a specific resolution. Such a test unfortunately does not exist because different applications have different requirements from a system. For instance 3d apps require CPU, memory and graphics card performance as well as motherboard bridge data transferring speed, while web browsing mostly needs memory.

The closest thing to a standardized test that I can think of, is video reproduction. To avoid having bought the screen just to realize that it cannot reproduce video at resolution X you can test it by playing back video in headless mode using X virtual framebuffer xvfb. Then you can get playback statistics using the method described here: https://forum.videolan.org/viewtopic.php?t=61867 And compare them with those of another machine.

I really hope this will help!

Answer 3

So after trawling the web for pages on this card I found the waybackmachine has a copy of the specs page from ATi

https://web.archive.org/web/20061006060608/http://www.ati.com/products/radeonxpress200/specs.html

Most importantly:

3D Graphics: Supports resolution up to 2536x2536@32bpp

2D Graphics: Supports a maximum resolution of 2048x1536@32bpp

External Support: Support for fixed resolution displays from VGA (640x480) to wide UXGA (1600x1200)

Answer 4

Have you looked at the "list all" list of resolutions in your display adapter properties? If I'm not horribly mistaken (possible!) that shows all of the supported video outputs from your video card, assuming you have the most recent drivers installed etc.

This was true for my old Radeon card in an old intel optiplex 745 - I tested on a monitor that could support higher resolutions, hacked the table to allow higher resolutions with the correct aspect ratio, and got no picture unless I used values lower than those listed in display adapter properties.