How to enable three monitors - nVidia Gt 610 (cannot find crtc for output...)

Ook · 06-21-2013, 12:17 PM

Slackware 14.0 64 bit
nVidia GT 610 video card

I'm trying to get three monitors to work. The card has a DVI output, an HDMI output, and a VGA output. I have a monitor connected to each of these. By using xrandr, I can get any combination of any two monitors to turn on at any time. I can NOT get all three monitors to turn on at the same time. If I have two on and try to enable the third, I get:

xrandr: cannot find crtc for output VGA-0

This is the output of xrandr -q --verbose:

Code:

Screen 0: minimum 8 x 8, current 3840 x 1080, maximum 16384 x 16384
DVI-I-0 disconnected (normal left inverted right x axis y axis)
	Identifier: 0x27b
	Timestamp:  3391270
	Subpixel:   unknown
	Clones:    
	CRTCs:      0 1
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter: 
	BorderDimensions: 
	Border: CARDINAL(6) (format 16 items 4) ????
	SignalFormat:	VGA
		supported: VGA         
	ConnectorType:	DVI-I
	ConnectorNumber: 0 (0x00000000)
	_ConnectorLocation: 0 (0x00000000)
VGA-0 connected (normal left inverted right x axis y axis)
	Identifier: 0x27c
	Timestamp:  3391270
	Subpixel:   unknown
	Clones:    
	CRTCs:      0 1
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter: 
	EDID:
		00ffffffffffff0010ac004042354241
		0f0e01030e261f78ee6f86a25a4d9424
		1a4f54a54b00714f8180010101010101
		010101010101302a009851002a403070
		1300782d1100001e000000ff00355932
		3332343435414235420a000000fc0044
		454c4c203139303146500a20000000fd
		00384c1e500e000a202020202020003e
	BorderDimensions: 
	Border: CARDINAL(6) (format 16 items 4) ????
	SignalFormat:	VGA
		supported: VGA         
	ConnectorType:	VGA
	ConnectorNumber: 2 (0x00000002)
	_ConnectorLocation: 2 (0x00000002)
  1280x1024 (0x27d)  108.0MHz +HSync +VSync +preferred
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock   64.0KHz
        v: height 1024 start 1025 end 1028 total 1066           clock   60.0Hz
  1280x1024 (0x27e)  135.0MHz +HSync +VSync
        h: width  1280 start 1296 end 1440 total 1688 skew    0 clock   80.0KHz
        v: height 1024 start 1025 end 1028 total 1066           clock   75.0Hz
  1152x864 (0x27f)  108.0MHz +HSync +VSync
        h: width  1152 start 1216 end 1344 total 1600 skew    0 clock   67.5KHz
        v: height  864 start  865 end  868 total  900           clock   75.0Hz
  1024x768 (0x280)   78.8MHz +HSync +VSync
        h: width  1024 start 1040 end 1136 total 1312 skew    0 clock   60.0KHz
        v: height  768 start  769 end  772 total  800           clock   75.0Hz
  1024x768 (0x281)   65.0MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  800x600 (0x282)   49.5MHz +HSync +VSync
        h: width   800 start  816 end  896 total 1056 skew    0 clock   46.9KHz
        v: height  600 start  601 end  604 total  625           clock   75.0Hz
  800x600 (0x283)   40.0MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock   37.9KHz
        v: height  600 start  601 end  605 total  628           clock   60.3Hz
  640x480 (0x284)   31.5MHz -HSync -VSync
        h: width   640 start  656 end  720 total  840 skew    0 clock   37.5KHz
        v: height  480 start  481 end  484 total  500           clock   75.0Hz
  640x480 (0x285)   25.2MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock   31.5KHz
        v: height  480 start  490 end  492 total  525           clock   59.9Hz
DVI-I-1 connected 1920x1080+0+0 (0x287) normal (normal left inverted right x axis y axis) 531mm x 299mm
	Identifier: 0x286
	Timestamp:  3391270
	Subpixel:   unknown
	Gamma:      1.0:1.0:1.0
	Brightness: 1.0
	Clones:    
	CRTC:       1
	CRTCs:      0 1
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter: 
	EDID:
		00ffffffffffff0010ac7fa053463630
		0916010380301b78ea3d25a35951a025
		0f5054a54b00714f8180d1c001010101
		010101010101023a801871382d40582c
		4500132b2100001e000000ff004e444d
		5250323333303646530a000000fc0044
		454c4c205032323132480a20000000fd
		00384c1e5311000a2020202020200085
	BorderDimensions: 
	Border: CARDINAL(6) (format 16 items 4) ????
	SignalFormat:	TMDS
		supported: TMDS        
	ConnectorType:	DVI-I
	ConnectorNumber: 0 (0x00000000)
	_ConnectorLocation: 0 (0x00000000)
  1920x1080 (0x287)  148.5MHz +HSync +VSync *current +preferred
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock   67.5KHz
        v: height 1080 start 1084 end 1089 total 1125           clock   60.0Hz
  1280x1024 (0x27e)  135.0MHz +HSync +VSync
        h: width  1280 start 1296 end 1440 total 1688 skew    0 clock   80.0KHz
        v: height 1024 start 1025 end 1028 total 1066           clock   75.0Hz
  1280x1024 (0x27d)  108.0MHz +HSync +VSync
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock   64.0KHz
        v: height 1024 start 1025 end 1028 total 1066           clock   60.0Hz
  1152x864 (0x27f)  108.0MHz +HSync +VSync
        h: width  1152 start 1216 end 1344 total 1600 skew    0 clock   67.5KHz
        v: height  864 start  865 end  868 total  900           clock   75.0Hz
  1024x768 (0x280)   78.8MHz +HSync +VSync
        h: width  1024 start 1040 end 1136 total 1312 skew    0 clock   60.0KHz
        v: height  768 start  769 end  772 total  800           clock   75.0Hz
  1024x768 (0x281)   65.0MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  800x600 (0x282)   49.5MHz +HSync +VSync
        h: width   800 start  816 end  896 total 1056 skew    0 clock   46.9KHz
        v: height  600 start  601 end  604 total  625           clock   75.0Hz
  800x600 (0x283)   40.0MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock   37.9KHz
        v: height  600 start  601 end  605 total  628           clock   60.3Hz
  640x480 (0x284)   31.5MHz -HSync -VSync
        h: width   640 start  656 end  720 total  840 skew    0 clock   37.5KHz
        v: height  480 start  481 end  484 total  500           clock   75.0Hz
  640x480 (0x285)   25.2MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock   31.5KHz
        v: height  480 start  490 end  492 total  525           clock   59.9Hz
HDMI-0 connected 1920x1080+1920+0 (0x287) normal (normal left inverted right x axis y axis) 531mm x 299mm
	Identifier: 0x288
	Timestamp:  3391270
	Subpixel:   unknown
	Gamma:      1.0:1.0:1.0
	Brightness: 1.0
	Clones:    
	CRTC:       0
	CRTCs:      0 1
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter: 
	EDID:
		00ffffffffffff0010ac7fa053343630
		0916010380301b78ea3d25a35951a025
		0f5054a54b00714f8180d1c001010101
		010101010101023a801871382d40582c
		4500132b2100001e000000ff004e444d
		5250323333303634530a000000fc0044
		454c4c205032323132480a20000000fd
		00384c1e5311000a20202020202000a9
	BorderDimensions: 
	Border: CARDINAL(6) (format 16 items 4) ????
	SignalFormat:	TMDS
		supported: TMDS        
	ConnectorType:	HDMI
	ConnectorNumber: 1 (0x00000001)
	_ConnectorLocation: 1 (0x00000001)
  1920x1080 (0x287)  148.5MHz +HSync +VSync *current +preferred
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock   67.5KHz
        v: height 1080 start 1084 end 1089 total 1125           clock   60.0Hz
  1280x1024 (0x27e)  135.0MHz +HSync +VSync
        h: width  1280 start 1296 end 1440 total 1688 skew    0 clock   80.0KHz
        v: height 1024 start 1025 end 1028 total 1066           clock   75.0Hz
  1280x1024 (0x27d)  108.0MHz +HSync +VSync
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock   64.0KHz
        v: height 1024 start 1025 end 1028 total 1066           clock   60.0Hz
  1152x864 (0x27f)  108.0MHz +HSync +VSync
        h: width  1152 start 1216 end 1344 total 1600 skew    0 clock   67.5KHz
        v: height  864 start  865 end  868 total  900           clock   75.0Hz
  1024x768 (0x280)   78.8MHz +HSync +VSync
        h: width  1024 start 1040 end 1136 total 1312 skew    0 clock   60.0KHz
        v: height  768 start  769 end  772 total  800           clock   75.0Hz
  1024x768 (0x281)   65.0MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  800x600 (0x282)   49.5MHz +HSync +VSync
        h: width   800 start  816 end  896 total 1056 skew    0 clock   46.9KHz
        v: height  600 start  601 end  604 total  625           clock   75.0Hz
  800x600 (0x283)   40.0MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock   37.9KHz
        v: height  600 start  601 end  605 total  628           clock   60.3Hz
  640x480 (0x284)   31.5MHz -HSync -VSync
        h: width   640 start  656 end  720 total  840 skew    0 clock   37.5KHz
        v: height  480 start  481 end  484 total  500           clock   75.0Hz
  640x480 (0x285)   25.2MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock   31.5KHz
        v: height  480 start  490 end  492 total  525           clock   59.9Hz

I notice that there are only 2 crtc's available. Does that mean it only allows two displays to be turned on at any one time? I can't find a good definition of exactly what a crtc is. Nor can I find any specs on this card that definitely say it does or does not support three monitors.

So - is it possible to have three monitors on at the same time with this card?

Ook · 06-21-2013, 01:20 PM

PS: I have another box with an nVidia 660, which has four crtcs, and it supports four monitors. At this point I'm fairly sure that the number of crtcs determines how many displays it can enable at once. Anyone able to confirm or correct this assumption?

wjcofkc · 12-06-2013, 05:11 AM

I see that your post was never answered, I have the same video card and was wondering if you ever figured anything out...

wjcofkc · 12-06-2013, 08:57 AM

I found my answer. It is not possible.

mattca · 12-06-2013, 09:19 AM

I'm not an expert, but I think the number of CRTCs determines the number of displays you can use at once. I have a dock with multiple display outputs that I've tried using 3 displays with. xrandr sees all 3, and I can enable any combination of 2, but when I try to enable the 3rd I get the above error.

I think the point of multiple outputs is to allow you to use different types of monitors, not necessarily to use all of the outputs at once.

wjcofkc · 12-06-2013, 09:24 AM

It turns out that on the 610 the DVI & HDMI share the same controller, making three monitors impossible. I would need to get at minimum a 640 to have three monitors. That's what happens when you go super cheap : )

mattca · 12-06-2013, 10:00 AM

You can also use a USB to VGA adapter. 14.1 comes with xrandr 1.4, which supports displaylink devices out of the box, using the udl driver (blacklist udlfb). It's a little laggy, but it works.