Since not much has been disclosed about the inner workings behind what probably is one of the most interesting concepts in gaming as of late, we can do nothing but speculate about what REALLY is needed for this new way of frame syncing to work.
From what Nvidia said, we know the following is required:
- Kepler uArch, specifically 650 ti and above.
- A supported monitor. By the asus one's specs, we can infer: 120/144hz capability. We still dont know if it's tied to a Panel technology, but right now only TN is discussed as it is the most fit for the task.
- A DP output. This is bolded because I think that, after being modded, losing the other outputs it's not a coincidence and the DP is key in allowing the dynamic vertical refresh to happen.
- The mod in question, that is shaped as a piece of PCB that should replace one of those 2 PCBs that are behind the panel when you mod your monitor. This is currently priced at 170 bucks, but they hope to get it lower.
So, what exactly does this PCB that the one that it replaces can't? Does it add the dynamic refresh rate functionality or just enables it? CRTs really could only work with fixed refresh rates because of the tech behind those monitors.
Now, in the era of LCDs, it isn't really needed because there is now persistence and they can hold an image without the need to refresh at a fixed rate if the image didn't change. So we could have had this technology earlier if it weren't for the need to keep CRT compatibility and the need of a refresh rate they (as in, monitor manufacturers) knew to make into a custom.
My assumption in the end is that monitor manufactures could have this feature incorporated a long ago, but following the motto "dont fix what it isnt broken" they stayed with fixed refresh rates even when it wasn't needed. The PCB to mod targets this point specifically and enables the feature, while the DP output may be the only one capable of dictating the refresh commands the other way around (that is now, from the GPU to the monitor) and thus is the only one up for the task. Last but not least, there might be in fact a requeriment for some kind of hardware frame metering needed, giving validity to the Kepler only requeriment.