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Old 05-23-12, 02:39 PM   #1
waperboy
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Join Date: Sep 2010
Posts: 11
Default Allow pixel clock > 400MHz

Tech is moving on, and people are actually running 2560x1440 resolution at 120+ Hz. Removal of 400MHz pixel clock limit in Linux drivers is requested.

Tested on 295.40 and 295.49.

This should actually work on a GTX 680, and people have used such timings in Windows:

Code:
ModeLine       "2560x1440_120" 478.785 2560 2608 2640 2704 1440 1443 1448 1475 +hsync +vsync
Option         "UseEdid" "FALSE"
Option         "ExactModeTimingsDVI" "TRUE"
Option         "ModeValidation" "NoVertRefreshCheck, NoHorizSyncCheck, NoDFPNativeResolutionCheck, NoMaxSizeCheck, NoMaxPClkCheck, NoEdidMaxPClkCheck, NoEDIDModes"
But get this:
Code:
[    19.217] (II) NVIDIA(0):   Validating Mode "2560x1440_120":
[    19.217] (II) NVIDIA(0):     2560 x 1440 @ 120 Hz
[    19.217] (II) NVIDIA(0):     Mode Source: X Configuration file ModeLine
[    19.217] (II) NVIDIA(0):       Pixel Clock      : 478.79 MHz
[    19.217] (II) NVIDIA(0):       HRes, HSyncStart : 2560, 2608
[    19.217] (II) NVIDIA(0):       HSyncEnd, HTotal : 2640, 2704
[    19.217] (II) NVIDIA(0):       VRes, VSyncStart : 1440, 1443
[    19.217] (II) NVIDIA(0):       VSyncEnd, VTotal : 1448, 1475
[    19.217] (II) NVIDIA(0):       H/V Polarity     : +/+
[    19.217] (II) NVIDIA(GPU-0):     BestFit Scaled and BestFit AspectScaled are identical;
[    19.217] (II) NVIDIA(GPU-0):         collapsing BestFit AspectScaled.
[    19.217] (II) NVIDIA(GPU-0):     BestFit Centered and BestFit Scaled are identical;
[    19.217] (II) NVIDIA(GPU-0):         collapsing BestFit Scaled.
[    19.217] (WW) NVIDIA(GPU-0):     BestFit Centered ViewPort 2560x1440 exceeds hardware
[    19.217] (WW) NVIDIA(GPU-0):         capabilities.
[    19.217] (WW) NVIDIA(0):     Mode is rejected: Unable to construct hardware-specific
[    19.217] (WW) NVIDIA(0):     mode timings.

...or am I missing something?

Timings that DO work, include:

Code:
ModeLine       "2560x1440_100" 400.000 2560 2592 2612 2692 1440 1443 1448 1480 +hsync +vsync
ModeLine       "2560x1440_102" 400.000 2560 2592 2612 2692 1440 1442 1446 1456 +hsync +vsync
ModeLine       "2560x1440_103" 400.000 2560 2592 2612 2692 1440 1441 1442 1444 +hsync +vsync
but anything with a pixel clock above 400 is summarily rejected, although the hardware can use it.
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