DLPLCR6500EVM: Getting 120 fps in video mode over display port

Hello Ivan,

Have you tried temporarily using the DLPLCR6500EVM as the only display and then setting it to 60 and then back up to 120.  Windows can be very particular about settings on DisplayPort.

Let me know if this gets it to run at 120 Hz.

Have you also tried it in Single Pixel mode?

Fizix

Hi Fizix,

Thank you for the response and the idea. I have tried to use the DMD as the single display but it did not help. I have also tried Single Pixel mode as well as lower resolutions in different combinations with color modes and Dual/Single pixel. Here is what I am trying out right now:

The DLP LightCrafter 6500 and 9000 EVM User's Guide (Rev. C) says:

The info on the DLPC900 Digital Controller Data Sheet is as follows:



These parameters can be found in the advanced timings settings of the Nvidia control panel.

I tried to match the settings to the requirements but so far have not succeeded. One reason is that datasheet parameter names differ from the parameters in the control panel and some are not present at all. The datasheet's 370us +2 lines are not quite clear to me. Back porch isn't in the control panel at all, Sync width isn't in the datasheet.

The CVT reduced blank standard as on the screenshot doesn't work, the DMD shows gray tone. Trying manual settings often results in the screen not showing anything at all as well or some fragments of the picture. I looked at the DLP EDID to get the timing information. The manual resolution settings work (the DLP displays correct picture) when the Pixel clock is 297 MHz, but still I didn't get the 120 Hz.

I would appreciate some hints what to look at. Thank you,

Ivan



Appendix:

EDID Detailed Timing Descriptor 1:
Pixel Clock: 148.5MHz
Horizontal Active: 1920
Horizontal Blanking: 280
Vertical Active: 1080
Vertical Blanking: 45
Horizontal Sync Offset: 88
Horizontal Sync Pulse: 88
Vertical Sync Offset: 4
Vertical Sync Pulse: 5
Horizontal Display Size: 1920
Vertical Display Size: 1080
Horizontal Border: 0
Vertical Border: 0
Interlaced: false
Stereo Mode: 0
Sync Type: 3

EDID Detailed Timing Descriptor 2
Pixel Clock: 297MHz
Horizontal Active: 1920
Horizontal Blanking: 280
Vertical Active: 1080
Vertical Blanking: 45
Horizontal Sync Offset: 88
Horizontal Sync Pulse: 88
Vertical Sync Offset: 4
Vertical Sync Pulse: 5
Horizontal Display Size: 1920
Vertical Display Size: 1080
Horizontal Border: 0
Vertical Border: 0
Interlaced: false
Stereo Mode: 0
Sync Type: 3

Hey, another follow-up

Nothing has worked so far for me, but I've tried quite a lot things to configure in custom resolution timings. And I've got question I've got is on the  DLPC900 Digital Controller Data Sheet:

The Pixel clock achieved can not be 138.4MHz using 2060x1120 total pixels per frame, according to the graphics card control panel I get exactly double value:

This led me to trying lower resulotion providing clock under 141 MHz but still only 60 fps are displayed.

Hi Fizix,

It's been a while and unfortunately I'm still stuck with the framerate problem. I have shared here the things I've tried so far, maybe you coud give an insight what I should focus on?

Thank you,
Ivan

Ivan,

I am sorry for the delay.  I have verified that you must use dual pixel to get to 120.  The ITE chip is capable of 120 on Display Port.

Make sure that the Graphics driver you are using is up to date.  

Have you tried a different (as in a different GPU) computer or if a desktop, a different GPU.  The Intel Integrated Graphics sometimes can be finicky.  See if you can borrow a colleague's or friend's laptop for a couple of hours to see if you can try it out.

Please let me know.

Fizix

Hello Fizix,

Still no luck with 120 fps. I used the vsynctester and similar testufo which use browsers' capabilities to sync with the framerate and Google Chrome as claimed supports this best. A few things I found:

- According to the tests, even if the DLP display is set to 120 hz, the vsync is running at 60 hz if there's another 60 hz display attached. I therefore ran all the tests with the DMD as single display only.

- Even when the vsync is measured at 120 hz, the DMD still displays 60 fps.

- As you have suggested I have tested it on other configurations and OS which I found available: Similar Nvidia Quadro K620 but with WIndows 8, Some other laptop with WIn 10 and Intel HD graphics and couple of macbooks. In all cases I ensured that the vsync is 120 hz and Chrome's debug info reports 120 fps. The filmed fps was still 60 in all cases.

I wanted to try a regular 120 hz display to see if my system is capable to use it and to be sure the problem is in the DMD, but unfortunately I did not find one test.

I still believe that it has something to do with the signal settings, I would like to learn in more details how the DMD decodes it, what exactly the Dual Pixel mode does (for example why the dmd look slightly changes when I switch to it the image appers slightly less contrast). Unfortunately there is very little information about this in the datasheets.

Any ideas would help.

Ivan