Apple Cinema Display HD only shows 1280 x 800 available...

Jaime Gago · 10-28-2010, 10:27 PM

I have an Apple Cinema Display HD (30") connected to a MacBook Pro via a SEWELL Minideck (USB to DVI) and the only resolution available is 1280 x 800.

Sewell Tech Support redirected me here.

I'm attaching the info from the debug tool.

scubadave · 10-29-2010, 12:19 AM

It sounds like a simple detection bug, whatever code their developers have written is failing to recognize native resolutions properly...

I suspect, there is a quick fix, if only the code was open source...

Pawel · 10-29-2010, 03:31 PM

scubadave - no it is not a detection bug and the software detects available resolutions properly. The reason why Jaime Gago sees 1280 x 800 as the only resolution available is that according to the logs, his monitor only supports 2 modes:

"Display Modes
--------------
1280x800x24@60
2560x1600x24@60"

2560x1600x24@60 is not supported by SEWELL Minideck (USB to DVI).

Regards

Jaime Gago · 10-29-2010, 10:18 PM

Can you be more precise?
Technically the monitor (Apple Cinema HD) *does* support much more than those 2 resolutions modes.
If I connect it via the Mini Display link I have many resolutions options. So why is there only 1 available when connected on the Sewell Minideck? Why are the logs reporting only those 2 modes when the display is capable of much more?

Carlo · 11-01-2010, 10:57 AM

Quote:

Originally Posted by Jaime Gago

Can you be more precise?
Technically the monitor (Apple Cinema HD) *does* support much more than those 2 resolutions modes.
If I connect it via the Mini Display link I have many resolutions options. So why is there only 1 available when connected on the Sewell Minideck? Why are the logs reporting only those 2 modes when the display is capable of much more?

All Apple displays from the ADC ones onwards don't have an onboard scaler and thus support only the native resolution. The exception are the 30" displays that also support the one-quarter resolution that is easy to obtain without a scaler.
What happens when you connect these displays directly to your Mac is that the graphics card makes more resolutions available by performing full screen scaling. In other words, the GPU does the scaling instead of the display.
DisplayLink drivers don't have this additional full-screen scaling function (yet).
I can't give a date for this feature, it is not in high demand because usually the displays are used at their native resolution anyway. In your case of course this is not possible.

Jaime Gago · 11-01-2010, 09:30 PM

Thanks Carlo, that makes it _at last_ clear.

10-29-2010, 03:31 PM	#3
Pawel Moderator Join Date: Aug 2010 Posts: 214	scubadave - no it is not a detection bug and the software detects available resolutions properly. The reason why Jaime Gago sees 1280 x 800 as the only resolution available is that according to the logs, his monitor only supports 2 modes: "Display Modes -------------- 1280x800x24@60 2560x1600x24@60" 2560x1600x24@60 is not supported by SEWELL Minideck (USB to DVI). Regards Last edited by Pawel; 10-29-2010 at 03:34 PM.

10-29-2010, 10:18 PM	#4
Jaime Gago Junior Member Join Date: Oct 2010 Posts: 4	Can you be more precise? Technically the monitor (Apple Cinema HD) does support much more than those 2 resolutions modes. If I connect it via the Mini Display link I have many resolutions options. So why is there only 1 available when connected on the Sewell Minideck? Why are the logs reporting only those 2 modes when the display is capable of much more? Last edited by Jaime Gago; 10-29-2010 at 10:28 PM.

10-29-2010, 12:19 AM	#2
scubadave Junior Member Join Date: Oct 2010 Posts: 8	It sounds like a simple detection bug, whatever code their developers have written is failing to recognize native resolutions properly... I suspect, there is a quick fix, if only the code was open source...

11-01-2010, 09:30 PM	#6
Jaime Gago Junior Member Join Date: Oct 2010 Posts: 4	Thanks Carlo, that makes it _at last_ clear.