I changed the second display card “GeForce 6600 GT” because it is broken. New display card is sapphire x1550 (ati - radeon).
xorg.conf file
Section "ServerLayout"
Identifier "layout"
Screen 0 "nvidia"
Inactive "radeon"
EndSection
Section "Device"
Identifier "nvidia"
Driver "nvidia"
BusID "01:00:00"
EndSection
Section "Screen"
Identifier "nvidia"
Device "nvidia"
Option "AllowEmptyInitialConfiguration"
EndSection
Section "Device"
Identifier "radeon"
Driver "modesetting"
EndSection
Section "Screen"
Identifier "radeon"
Device "radeon"
EndSection
output of “lspci”
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD/ATI] RD890 PCI to PCI bridge (external gfx0 port B) (rev 02)
00:02.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] RD890 PCI to PCI bridge (PCI express gpp port B)
00:04.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] RD890 PCI to PCI bridge (PCI express gpp port D)
00:07.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] RD890 PCI to PCI bridge (PCI express gpp port G)
00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 SATA Controller [AHCI mode] (rev 40)
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:12.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:13.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 SMBus Controller (rev 42)
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 Azalia (Intel HDA) (rev 40)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 LPC host controller (rev 40)
00:14.4 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 PCI to PCI Bridge (rev 40)
00:14.5 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI2 Controller
00:15.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] SB700/SB800/SB900 PCI to PCI bridge (PCIE port 0)
00:16.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:16.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 0
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 3
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 5
**01:00.0 VGA compatible controller: NVIDIA Corporation GF116 [GeForce GTS 450 Rev. 2] (rev a1)
01:00.1 Audio device: NVIDIA Corporation GF116 High Definition Audio Controller (rev a1)**
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 09)
03:00.0 USB controller: ASMedia Technology Inc. ASM1042 SuperSpeed USB Host Controller
04:05.0 Network controller: Ralink corp. RT2561/RT61 802.11g PCI
04:06.0 Multimedia controller: Philips Semiconductors SAA7131/SAA7133/SAA7135 Video Broadcast Decoder (rev d1)
**05:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV516 [Radeon X1300/X1550 Series]
05:00.1 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] RV516 [Radeon X1300/X1550 Series] (Secondary)**
output of xrandx —listproviders
Providers: number : 2
Provider 0: id: 0x2b2 cap: 0x1, Source Output crtcs: 2 outputs: 4 associated providers: 0 name:NVIDIA-0
Provider 1: id: 0x44 cap: 0x2, Sink Output crtcs: 2 outputs: 3 associated providers: 0 name:modesetting
successful commands below.
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto
**But there is no signal on my third monitor.
**
I can see my third monitor on “Display Configuration - KDE Control Module”. It is acer x193HQ.
http://s1.postimg.org/ldmul6of3/kdeconfiguration.png
So I feel like we are close to solution. But I don’t understand. Why is there any signal on my third monitor?