How to tell which GPU is used to render?

[cbstryker]

So I've been having a bit of an issue with Lord of the Rings Online performance recently. I've played LOTRO in the past in CXGames (Crossover Games) for years and never had a problem, LOTRO always ran like a champ, even better than in Windows in some cases.

However, a little while ago I got a second video card to use as a simple VGA passthrough for a third monitor, and of course I want to do triplehead gaming. But I've been noticing, even with the game on only 1 monitor it's very laggy (when across more than 1 screen with settings set to lowest it's still laggy, but with just one screen it seems ok), almost as if it's using the slower card. So here is my system:

Ubuntu 10.04 64bit
Asus P5K Motherboard
Q6600 overclocked to 3.07GHz (stable)
8GB DDR2 overclocked to 1000Mhz (stable)
3 Monitors, each a separate X screen with Xinerama enabled.
GeForce 260 GT running screen 0 (main screen) and 1
GeForce 8400 GS running screen 2

Screens arranged as 2,0,1

When I type "glxheads" and "glxheads :0" both give me this:


chris@chris-ubuntu:~$ glxheads :0
Name: :0.0
Display: 0x68f6d0
Window: 0x5200002
Context: 0x6ba368
GL_VERSION: 3.3.0 NVIDIA 256.35
GL_VENDOR: NVIDIA Corporation
GL_RENDERER: GeForce 8400 GS/PCI/SSE2


Not sure if this is relevant but when I close the window this pops up:


XIO: fatal IO error 11 (Resource temporarily unavailable) on X server ":0.0"
after 63 requests (63 known processed) with 0 events remaining.


However, when I have separate X screen with Xinerama disabled the GL_RENDERER line says "GeForece 260 GT" when started from screen 0 or 1, screen 2 would still give me "GeForece 8400 GS".

So I think what's been happening is that everything has been using the 8400GS and not the 260GT this whole time, but how can I check this and how can I change it?

BTW, I've tried adding " :0" to the launcher for LOTRO with no effect, but then again glxheads had no impact with that either.

Any ideas?

[cbstryker]

anyone?

[cbstryker]

Please, I'm looking for input from anyone.

[dino99]

maybe some help here, look at dynamic-twinview & multigpu settings

http://manpages.ubuntu.com/manpages/lucid/man1/nvidia-xconfig.1.html

[cbstryker]

maybe some help here, look at dynamic-twinview & multigpu settings

http://manpages.ubuntu.com/manpages/lucid/man1/nvidia-xconfig.1.html

Hi, I appreciate the reply. I've looked over those before, but I can't make heads or tails as to which one will give me what I need.

Just as an update, when I disable the one screen on the second GPU, "glxheads" shows "GeForece 260 GT" in the output and the spinning graphic is almost a blur compared to doing it with the "GeForce 8400 GS". So this clearly is an issue of the wrong GPU being used.

[cbstryker]

I've found something to add. Notice towards the bottom it says "GeForce 8400 GS" and nowhere does it mention my GeForce 260 GTX.

The output of glxinfo:


chris@chris-ubuntu:~$ glxinfo
name of display: :0.0
display: :0 screen: 0
direct rendering: Yes
server glx vendor string: NVIDIA Corporation
server glx version string: 1.4
server glx extensions:
GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_SGIX_fbconfig,
GLX_SGIX_pbuffer, GLX_SGI_video_sync, GLX_SGI_swap_control,
GLX_EXT_swap_control, GLX_EXT_texture_from_pixmap, GLX_ARB_create_context,
GLX_ARB_create_context_profile, GLX_ARB_multisample, GLX_NV_float_buffer,
GLX_ARB_fbconfig_float, GLX_EXT_framebuffer_sRGB
client glx vendor string: NVIDIA Corporation
client glx version string: 1.4
client glx extensions:
GLX_ARB_get_proc_address, GLX_ARB_multisample, GLX_EXT_visual_info,
GLX_EXT_visual_rating, GLX_EXT_import_context, GLX_SGI_video_sync,
GLX_NV_swap_group, GLX_NV_video_out, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer,
GLX_SGI_swap_control, GLX_EXT_swap_control, GLX_ARB_create_context,
GLX_ARB_create_context_profile, GLX_NV_float_buffer,
GLX_ARB_fbconfig_float, GLX_EXT_fbconfig_packed_float,
GLX_EXT_texture_from_pixmap, GLX_EXT_framebuffer_sRGB,
GLX_NV_present_video, GLX_NV_copy_image, GLX_NV_multisample_coverage,
GLX_NV_video_capture
GLX version: 1.4
GLX extensions:
GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_SGIX_fbconfig,
GLX_SGIX_pbuffer, GLX_SGI_video_sync, GLX_SGI_swap_control,
GLX_EXT_swap_control, GLX_EXT_texture_from_pixmap, GLX_ARB_create_context,
GLX_ARB_create_context_profile, GLX_ARB_multisample, GLX_NV_float_buffer,
GLX_ARB_fbconfig_float, GLX_EXT_framebuffer_sRGB,
GLX_ARB_get_proc_address
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce 8400 GS/PCI/SSE2
OpenGL version string: 3.3.0 NVIDIA 256.35
OpenGL shading language version string: 3.30 NVIDIA via Cg compiler

[lukeiamyourfather]

Unless the system is using SLI I would guess the card the monitor is plugged into is the card doing the rendering. Without SLI/CrossFire the cards don't talk to each other or render anything elsewhere. Cheers!