Custom Resolution Utility (CRU)

[ToastyX]

(03-27-2013 11:13 PM)MS-DOS Wrote:  

(09-07-2012 09:06 PM)ToastyX Wrote:  Single-link DVI and HDMI are limited to 165 MHz pixel clock unless the video driver is patched

Are you serious? I thought it was a limit the the cable itself, not a software one.

The cable is just a data transfer medium. It can't impose a limit, although after a certain point, the signal will degrade. I've found most cables and video cards can handle at least 225 MHz per link.

The DVI spec says anything over 165 MHz must run in dual-link mode. This can be implemented in hardware or in software. In the case of video cards, I've found it's implemented in the driver.

In the case of monitors, single-link DVI monitors (1920x1200 and under) and HDMI ports always run in single-link mode, so dual-link signals will not work properly. They don't have the hardware to handle dual-link signals, but they can often handle single-link signals above 165 MHz.

I haven't found any monitor that needs dual-link mode under 235 MHz for the native resolution, so it's safe to raise this limit even on dual-link DVI ports. It also doesn't make sense to impose this limit on single-link DVI or HDMI ports since they can't run in dual-link mode anyway. The patches raise the limit in both cases.