SLI/MultiGPU drop FPS

love2hate · 12-09-09, 07:53 PM

Hi , thas week i get a 9800GX2 , i run first time with monogpu ( nvidia-settings say screen 0 gpu--> 9800GX2 GPU0 )
2 time i see the doc ( chapter 25 ) and make new xorg.conf with nvidia-xconfig --multigpu=on but after restart X i have realy poor fps ... I keep see the doc and fine more info with nvidia-xconfig --advanced-help , i fine some "tricks"
Enable or disable SLI. Valid values for SLI are 'Off', 'On', 'Auto', 'AFR', 'SFR', 'AA', 'AFRofAA'

After thas i go make some bench ( with phoronix-test-suite 2.2.0 etqw-demo and unigine tropics)
All bench run without 3D desktop effet

====================================
ET: Quake Wars Demo
Resolution: 1280 x 1024
====================================

test1: 64.71 sli off
test2: 21.76 sli SFR
test3: 43.36 sli AA
test4: 23.33 sli Auto

====================================
Unigine Tropics 1.2
Resolution: 1280 x 1024
====================================

test1: 47.5 sli OFF
test2: 14.7 sli auto
test3 32.3 sli sfr
ect .....

some infos

Processor: Intel Core 2 CPU 6420 @ 2.82GHz (Total Cores: 2), Motherboard: ASUSTeK P5K, System Memory: 2008MB, Disk: 74GB WDC WD740ADFD-00 + 500GB MAXTOR STM350032 + 82GB Excelstor Techno, Graphics: GeForce 9800 GX2 512MB (600/1000MHz

OS: Funtoo Linux - baselayout 2.1.6, Kernel: 2.6.32-gentoo (x86_64), Desktop: KDE, Display Server: X.Org Server 1.7.3, OpenGL: 3.2.0 NVIDIA 190.42, Compiler: GCC 4.3.3, File-System: reiserfs, Screen Resolution: 1920x1080
I make zip with xorg.conf emerge-info and some log
PS sorry for my poor english

wiresquire · 12-09-09, 11:55 PM

It's possible that those benchmarks aren't really suitable for testing your machine. Which benchmarks stress gpu over cpu etc varies a fair bit from machine to machine.

I have tested ET and saw same crazy results as you. I have also tested Unigine Tropics, and I had strange results. Sometimes results would vary a lot, and so I have come to the conclusion it is too heavy a test for my machine.

Can I suggest that you try Lightsmark 2008 ? It's also available in the phoronix suite. I have found it gives a good balance to test graphics, including SLI, for me.

HTH
ws

love2hate · 12-10-09, 10:21 AM

Ok to day i make another test/bench with Lightsmark 2008 but i get same crapy score

====================================
Lightsmark 2008
Resolution: 1920 x 1080
====================================

test1: 370.22 sli off
test2: 96.56 sli SFR
test3: 54.17 sli AA
test4: 209.99 sli auto

What wrong whit multigpu linux ? !!!!!

PS I can't run Lightsmark with Option "SLI" "on" , bench run after thas my desktop freez need hard reboot ( magic systeme key don't work :/)

wiresquire · 12-11-09, 02:44 PM

Something definitely looks strange there.
In my SLI tests, Lightsmark showed some improvement with SFR. Have you tried with multi-gpu set to AFR?

It may be worthwhile to attach a nvidia-bug-report also...

Good luck
ws

12-09-09, 11:55 PM	#2
wiresquire Registered User Join Date: Mar 2008 Posts: 81	Re: SLI/MultiGPU drop FPS It's possible that those benchmarks aren't really suitable for testing your machine. Which benchmarks stress gpu over cpu etc varies a fair bit from machine to machine. I have tested ET and saw same crazy results as you. I have also tested Unigine Tropics, and I had strange results. Sometimes results would vary a lot, and so I have come to the conclusion it is too heavy a test for my machine. Can I suggest that you try Lightsmark 2008 ? It's also available in the phoronix suite. I have found it gives a good balance to test graphics, including SLI, for me. HTH ws

12-10-09, 10:21 AM	#3
love2hate Registered User Join Date: Dec 2009 Posts: 2	Re: SLI/MultiGPU drop FPS Ok to day i make another test/bench with Lightsmark 2008 but i get same crapy score ==================================== Lightsmark 2008 Resolution: 1920 x 1080 ==================================== test1: 370.22 sli off test2: 96.56 sli SFR test3: 54.17 sli AA test4: 209.99 sli auto What wrong whit multigpu linux ? !!!!! PS I can't run Lightsmark with Option "SLI" "on" , bench run after thas my desktop freez need hard reboot ( magic systeme key don't work :/)

12-11-09, 02:44 PM	#4
wiresquire Registered User Join Date: Mar 2008 Posts: 81	Re: SLI/MultiGPU drop FPS Something definitely looks strange there. In my SLI tests, Lightsmark showed some improvement with SFR. Have you tried with multi-gpu set to AFR? It may be worthwhile to attach a nvidia-bug-report also... Good luck ws