10.14.3 GT640 dual monitor

[Johnnas]

Previously was on Sierra and dual monitor with GT640 worked great.
I'm currently on 10.14.3 and single monitor works perfect and Mojave detected the GT 640 correctly. However, can not get the dual monitor to work. No signal is detected by the secondary monitor. Monitor itself tests fine. GeForce website does not have a driver download for Mojave. Anything obvious I'm missing, other than it being an older graphics card?

Thank you

 

[itwas]

you may try the other port

In my setup
GT640 | 10.14.3 (18D109)
suppose it should works on both DVI-D ports, but it only detect One LCD Monitor
DVI + DVI -> only One Monitor detected

so I try HDMI port
DVI + HDMI -> Two LCD Monitors detected

DVI + HDMI

NVIDIA GeForce GT 640:



  Chipset Model:    NVIDIA GeForce GT 640

  Type:    GPU

  Bus:    PCIe

  PCIe Lane Width:    x16

  VRAM (Dynamic, Max):    2047 MB

  Vendor:    NVIDIA (0x10de)

  Device ID:    0x0fc1

  Revision ID:    0x00a2

  ROM Revision:    VBIOS 80.07.26.00.34

  Metal:    Supported, feature set macOS GPUFamily1 v4

  Displays:

DELL U2410:

  Resolution:    1920 x 1200 (WUXGA - Widescreen Ultra eXtended Graphics Array)

  UI Looks like:    1920 x 1200 @ 60 Hz

  Framebuffer Depth:    24-Bit Color (ARGB8888)

  Display Serial Number:   

  Main Display:    Yes

  Mirror:    Off

  Online:    Yes

  Rotation:    Supported

  Automatically Adjust Brightness:    No

DELL U2410:

  Resolution:    1920 x 1200 (WUXGA - Widescreen Ultra eXtended Graphics Array)

  UI Looks like:    1920 x 1200 @ 60 Hz

  Framebuffer Depth:    24-Bit Color (ARGB8888)

  Display Serial Number:   

  Mirror:    Off

  Online:    Yes

  Rotation:    Supported

  Automatically Adjust Brightness:    No

 

[Johnnas]

Thank you for the response. I tried a few different combinations, but I never get signal on more than one monitor and only from the first port. When I try just the hdmi port I also get no signal.

 

[itwas]

Thank you for the response. I tried a few different combinations, but I never get signal on more than one monitor and only from the first port. When I try just the hdmi port I also get no signal.

When I plug-in the 2nd DVI LCD cable, the primary LCD monitor video just trun off and on quickly, the macOS detected a new LCD monitor is connected, but it just refuse to shows the 2nd monitor.
If my memory is correct, on Sierra, my GT640 graphics card can connect up to 3 LCD monitors (DVI + DVI + HDMI).

 

[itwas]

further testing :

both Sierra / Mojave support 3 LCD monitors

my setup
DVI-1 -> 1st LCD
DVI-2 -> 2nd LCD
HDMI -> 3rd LCD (after boot up the macOS, need to re-plug the HDMI connector, system reports there is three LCD monitors connected.

macOS :
10.12.6 (16G1510) and 10.14.3 (18D109)

NVIDIA GeForce GT 640:

  Chipset Model:    NVIDIA GeForce GT 640
  Type:    GPU
  Bus:    PCIe
  PCIe Lane Width:    x16
  VRAM (Dynamic, Max):    2047 MB
  Vendor:    NVIDIA (0x10de)
  Device ID:    0x0fc1
  Revision ID:    0x00a2
  ROM Revision:    VBIOS 80.07.26.00.34
  Metal:    Supported, feature set macOS GPUFamily1 v4
  Displays:
DELL U2410:
  Resolution:    1920 x 1200 (WUXGA - Widescreen Ultra eXtended Graphics Array)
  UI Looks like:    1920 x 1200 @ 60 Hz
  Framebuffer Depth:    24-Bit Color (ARGB8888)
  Display Serial Number:    
  Main Display:    Yes
  Mirror:    Off
  Online:    Yes
  Rotation:    Supported
  Automatically Adjust Brightness:    No
DELL U2410:
  Resolution:    1920 x 1200 (WUXGA - Widescreen Ultra eXtended Graphics Array)
  UI Looks like:    1920 x 1200 @ 60 Hz
  Framebuffer Depth:    24-Bit Color (ARGB8888)
  Display Serial Number:    
  Mirror:    Off
  Online:    Yes
  Rotation:    Supported
  Automatically Adjust Brightness:    No
DELL U2410:
  Resolution:    1920 x 1200 (WUXGA - Widescreen Ultra eXtended Graphics Array)
  UI Looks like:    1920 x 1200 @ 60 Hz
  Framebuffer Depth:    24-Bit Color (ARGB8888)
  Display Serial Number:    
  Mirror:    Off
  Online:    Yes
  Rotation:    Supported
  Automatically Adjust Brightness:    No