Problems wit 2 monitors on my Radeon 9600

[RealViper]

Hey guys, 19 reviews and no one who has an idea?

If Direct3D doesn't work with the Radeon dual screen mode is there a possibility to speed up OpenGL?

[dvornik]

Most people use nvidia cards I guess (including myself)... Go to advanced display settings and see what it gives you. In OGL try different settings, like turning vertical synch off and stuff like that. Also there should be 2 modes of using dual monitors (don't know how it works on ATI cards) - try both. Ideally you would want to get OGL working properly, though.

[CgFX]

I think this is a well known issue and people have had trouble getting ATI to fix it. I would search the forum.

[matty429]

You've discovered the caca that is Ati dual monitors....

If you use say 2 monitors at 1280x1024
you get a full res of 2560x1024

ATI states in very hard to find ,fine print that all ATI cards are limited at a 2048x2048 3D res...

Soo it is virtually impossible to get the ATI card to work the way you want it to...

[CgFX]

Hmmm... Not sure about that one Matty. I can see ATI being limited to a hardware cursor or hardware overlay planes at a fixed resolution like that (2048x2048 is a common hardware cursor limit) but I would be surprised if ATI had a hard coded framebuffer size limit.

[RealViper]

Thank you all for reply.

@matty429: If I connect the TFT to my Laptop (ATI Mobility Radeon 7500, resolution 1400x1050 and TFT 1280x1024), 3dsMax works fine with Direct3D. I can work on both screens while Max is running! From there my thought was it has to work with my Radeon 9600pro, too. But it doesnt.

An my other question: What is the better choice: Direct3D or OpenGL? Until now I think it will be Direct3D, but I'm not shure.

[matty429]

Ok....

Whats this (http://www.extremetech.com/article2/0,3973,1156484,00.asp)

This still stands for new ATI cards as well

[matty429]

Yeah I had an old Radeon ve that was capable of ...actually spanning the desktop...Taskbar and all ...it was slow but the concept was right on...how come they can't do that with newer cards...?

I couldn't tell you on what rendering engine to use...If your'e making a game direct3d for sure...Opengl might be a little faster though...but I don't know I've been out of the Max loop since version 4

[imashination]

Thats the 3D viewport size, the 3D view itself cannot exceed 2048, which is a reasonable limit. You can be running a couple of 1920 screens if you like, with the 3d view on one screen and all the controls on another, but you cannot stretch the 3d view fully across both screens. You'd have a black bar down the middle for starters.

I've run a 9800pro as a dual with 1920x1200 and 1280x1024 on the second, no problems with a maximized 3d view on the large screen and the controls on the second one.

[matty429]

Thats all fine and dandy untill you have a program Like Maya that uses OpenGL for the majority of its windows....

[CgFX]

Originally posted by matty429
Ok....

Whats this (http://www.extremetech.com/article2/0,3973,1156484,00.asp)

This still stands for new ATI cards as well

Yikes.

[CgFX]

Originally posted by imashination
Thats the 3D viewport size, the 3D view itself cannot exceed 2048, which is a reasonable limit.
Not on my planet.

[RealViper]

Ok I see I cant let my Radeon 9600pro run with 2 monitors and Direct3D.

BTW: What do you prefer: Direct3D or OpenGL, and why? What is the better choice?

[imashination]

Originally posted by CgFX
Not on my planet.

1) What possible situation would give you a single 3D view over 2048 wide?

2) There is no 2048 limit anyway

www.imashination.com/files/ati.jpg

[CgFX]

Originally posted by imashination
1) What possible situation would give you a single 3D view over 2048 wide?
The very example that you yourself provide in point #2.

2) There is no 2048 limit anyway

www.imashination.com/files/ati.jpg
Are you sure you didn't get booted to software (CPU) mode at that point. With such simple geometry a P4 is more than fast enough to make you believe you are still in hardware accelerated OpenGL. Try 100,000 texture-mapped polygons with your example and see if your perf falls off a cliff.

Again, I don't understand why ATI would be so dumb as to have such a low, hard-coded framebuffer limit but all the reading I have done since this was pointed out to me suggest it may be true.

[RealViper]

0k guys, thank you all for your answers.

I SOLVED THE PROBLEM, yiiippieeehhh!

I changed the analog cable from my CRT to a digital and - it works!!!!

[Kemper_Boyd]

Just a data point FWIW.

Radeon 9700, Win2k, Catalyst 3.10.

I just ran two copies of my own app, one screen
at 1280x1024 and the other at 1280x960. It's
definitely not falling back to software as I wrote
the code and it uses fragment shaders which
would be insanely slow in software.

Spanning the centre of the screen works too. :)

Also FWIW the maximum viewport supported
for OpenGL in the 3.10 driver is 4096x4096 so
you could drive one of those Big-Bertha TFTs
in theory.

I've just checked an OpenGL windows across two screens,
2560x960 works just fine. You should be able to have
a viewport, or ports, up to 4096x4096 or when you run
out of VRAM for the front/back/depth/overlay buffers
that are required. Geometry and textures can get punted
to system RAM by the driver.

IMHO ATI's OpenGL multi-monitor support is very
good, certainly better than Nvidia's used to be.

I've done a fair bit of multi-monitor and multi-card
OpenGL programming and ATI's drivers are just
as good as anyone elses in my experience.

I can't think of any reason for cables making a difference
though. :hmm:

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