Originally Posted by Smykster
Okay, as per Ken's request once again, I'll clear up some misinformation regarding cable bandwidth and monitor refresh rates:
My message to Ken:
KK, did some number crunching for you. The effective data rate of a dual link DVI cable is 7.92 Gbits/second. With this in mind, the highest resolution dual link DVI supports at 120hz is 1920*1200. How do we know this? 1920*1200 = 2,304,000 pixels, 2304000 x 120(hz) = 276,480,000 x 24(bit color) = 6,635,520,000 or 6.63 Gbits/sec.
For a resolution of 2560*1440, lets do the math:
2560*1440 = 3,686,400 x 120(hz) = 442,368,000 pixels per second x 24(bit color) = 10,616,832,000 bits per second or 10.6 Gbits/second.
Dual-link DVI effective data rate = 7.92 Gbits/sec
HDMI 1.3/1.4 effective data rate = 8.16 Gbits/sec
DisplayPort 1.0/1.1 effective data rate = 8.64 Gbits/sec
2560*1440 @ 120hz = 10.61=Gbits/sec which is well over all of these.
Displayport 1.2 effective data rate = 17.28 Gbits/sec
HDMI Type B effective data rate = 20.40 Gbits/sec
Those would work with 2560*1440 @ 120hz
From the write up I did, I would hypothesize that the hardware is indeed pumping out 2560*1440 @ 120hz or greater, but the bandwidth is being exceeded and the monitor is is not showing many of the frames. Just like when you're gaming at 120hz yet you have a 60hz monitor, you're missing half the frames the hardware is pumping out.