Originally Posted by Paps.pt
Then we must ask: Why hasent Samsung, LG or Dell come up with a PLS/IPS monitor that works at 120 or even 96Hz yet?
This generation of panel isn't capable of it without overclocking. There are several pieces to the chain that goes from the PC to your eyes, and the limiting factor here is in the panel electronics.
The PC sends the signal out in DVI or DisplayPort format, then there is a chip that converts that to another format called LVDS, and the LVDS signal is then in turn used by another chip to drive the actual pixels. This DVI/LVDS converter is basically the centerpiece of the Overlord PCBs. The DVI/DisplayPort receiver chip (which also deals with scaling, color conversion, OSDs, HDCP, and all the other stuff that is needed in a real-world display) is fairly standard but the actual driver chip is made by the panel maker to go with that specific panel. It just happened that some of the simpler DVI to LVDS converter chips (and, in turn the panel drivers) were overclockable. I believe this is the reason that there are color problems at high refresh on these panels: the driver chip doesn't have time to set the pixels properly before the next ones come in.
LVDS is a little like PCIe, the bandwidth is based on how many lanes there are. Unfortunately driving a high-resolution panel at 120Hz without going out of spec requires four LVDS lanes, but nobody makes a PLS/IPS driver chip that handles more than two. Of course, Samsung could make a four-lane LVDS chip to go with the panel but they have not, probably because they didn't know there would be a market for it (perhaps there might actually not be, or not enough of one). Adding LVDS lanes is a real cost to them, because each LVDS lane needs more circuit board space and its own wiring bundle as well as more expensive DP/DVI and panel driver chips. So to build such a thing requires a conscious decision by them to support 120Hz in a large-format monitor at a higher price.
Similarly a low resolution panel (1080p) is usually just one LVDS lane, but the 120/144Hz panels are two-lane. Unfortunately you can't take a two-lane LVDS chip off of a 120Hz TN panel and move it to an IPS/PLS panel because the driver chip is specific to the panel it goes with. LG probably has a two-lane 120Hz panel driver for 120Hz IPS TVs that could be adapted to a smaller (1080p) IPS panel, so I'd expect to see the first good-color-quality 120Hz monitors being 1920x1080 IPS.
The long range plan for manufacturers is to move to DisplayPort inside the monitor as well and stop using LVDS, and that will solve this particular problem, but nobody is doing that yet (AFAIK). It would also solve all the various DVI cabling problems, DVI is pretty marginal for high refresh at these resolutions. Maybe the 4K TVs or 2013 Dells are doing it, I don't really know. These panels certainly aren't.
The real improvement in motion blur comes from LightBoost (really, from strobing backlight, Lightboost is the whole end-to-end 3D system). It would be useless for 3D, but for gaming you could get good-quality motion blur at 90Hz with a strobe backlight. This would however cause almost a whole frame of lag (Lightboost now does, as well) but the lower the refresh rate, the more significant that becomes. At 120Hz, it's clearly worth it. At 90Hz, it's a little more questionable. At frequencies lower than 90Hz, flicker would start to become a problem. I don't consider myself terribly flicker-sensitive, but 85Hz is the minimum CRT refresh rate that doesn't cause eyestrain for me.Edited by fluffysheap - 5/24/13 at 5:45pm